Cogenra Solar Delivers Hot Water Along with Power

The solar power system Facebook Inc. plans for its new Menlo Park headquarters won't just supply electricity. It'll heat water for the showers, too. And maybe help clean dishes in the cafe.


The system will be designed and installed by Cogenra Solar, a Mountain View startup that uses the sun's energy to produce electricity and hot water at the same time. The collection of solar cells, mirrors and pipes will sit atop Facebook's 10,000-square-foot fitness center, powering the exercise equipment and churning out steaming water for the locker rooms.

The technology's dual use makes it far more cost-effective than conventional solar systems that provide electricity alone, said Cogenra CEO Gilad Almogy. And while neither company will say how much the array will cost Facebook, Almogy said the social networking giant will recoup its investment in less than five years.

"It'll be a shorter payback than any other form of renewable energy," Almogy said.

Planting solar panels on the office or warehouse roof has become de rigueur for many Bay Area companies. By those standards, Facebook's solar array will be small, generating just 10 kilowatts of electricity. A typical home solar system produces about 3 kilowatts.

The array will cover only one roof on the nine-building campus, which used to house Sun Microsystems. But Facebook could expand the system if it performs as advertised, possibly using the hot water in the existing cafe and another planned for the campus. John Tenanes, Facebook's director of global facilities, said his company is taking the same approach to solar that it takes to its Web service - checking out a promising new idea to assess its potential.

"We try stuff and see if it works," he said. "And that's what this is. Cogenra is really our initial investment (in solar power), and we're going to see how well it works."

Cogenra's technology is designed to use energy that other solar set-ups waste.

Photovoltaic panels absorb a small fraction of the energy the sun throws at them, typically 15 to 20 percent. The rest is wasted as heat.

Cogenra arrays, however, run fluid-filled tubes behind the solar cells, with the fluid absorbing some of the heat cast off by the cells. The fluid - a chemical compound kept in a sealed loop - then transfers the heat to water. Curved troughs of mirrors concentrate sunlight on the cells, while motors keep the troughs pointed at the sun as it arcs across the sky.

Cogenra has already installed a 272-kilowatt system at a Sonoma winery, which uses the hot water to clean barrels. The Sonoma Wine Co. array, however, is mounted on the ground. The Facebook array will rest on the rooftop and will weigh far less. The company also plans to install a rooftop version of its technology on a University of Arizona dormitory.

"Not all customers who need significant amounts of hot water have nearby land to use," Almogy said.

Backed by Khosla Ventures, Cogenra also tries to keep costs down by using solar cells, inverters, mirrors and tracking equipment made by other companies. The company's ability to take off-the-shelf gear and turn it into something new impressed Facebook.

"They mashed together all these different things, and it seems to work well together," Tenanes said.

Source: http://www.sfgate.com/cgi-bin/article.cgi?f=/c/a/2011/11/02/BUA41LP7D0.DTL&type=tech

Solar Hot Water Rebates Now Being Paid

Thousands of homeowners who installed solar hot water can expect to finally receive their rebates by the middle of March.

About 8000 Australians have been waiting beyond the accepted eight-week timeframe for their rebates, worth between $1000 and $1600 each.

The federal government blamed a computer software problem for the backlog, but has reportedly rushed in a team of extra workers to help clear the list.


The energy efficiency department's Alex Rankin told a Senate estimates hearing on Monday that people could expect to get their money by the middle of next month.

Ms Rankin could not say how long homeowners had been waiting, amid reports some rebates have been stalled by up to 19 weeks.

"It's hard to tell at the moment because (it's) part of the transition from the old IT system," she said.

The troublesome software transfer also meant the department was slowly uncovering new claims, previously unseen.

"So we're currently going through a forensic exercise to try and identify each one of those and their current status," Ms Rankin said.

Deputy secretary Martin Bowles earlier faced scrutiny over the government's botched home insulation program, under which 1.2 million homes were insulated.

There is about $700 million left in funding, even though the program itself was scrapped last year.

Mr Bowles denied some of the leftover money will go towards compensation.

"Yes, there are a number of claims on the department," he told the hearing.

"But that does not mean that we accept any of those, and we have not paid any of those.

"We don't necessarily agree that there is a legal claim against the commonwealth."

The axed stimulus scheme was linked to four deaths and house fires.

SOURCE: http://news.smh.com.au/breaking-news-national/solar-rebates-to-be-paid-by-march-govt-20110221-1b2dp.html

Good News for Solar Hot Water System Rebates

Good news for New Hampshire residents mulling over the idea of buying solar powered hot water systems: a new mix of federal and state rebates and tax credits.

The state's Public Utilities Commission has expanded its maximum rebate to $2,900.

Broken down, that's a maximum $2,000 from federal stimulus money (which was raised from $750) plus a maximum $900 available from New Hampshire's renewable energy program. And another piece of good news: folks getting the maximum $2,900 rebate can also get a 30 percent federal tax credit.

Not everybody gets the maximum, though.

The amount of your rebate depends on the power potential of your solar system.

Kate Epsen of the PUC explained that if you purchase a $10,000 system that produces 6 to 19.9 MBTU (million British Thermal Units), the mixed state and federal incentive, plus the IRS federal tax credit, can be as much as $5,000.

For systems that are 20 to 29.9 MMBTU, the number goes to $5,150 available and for systems of 30 MMBTU or higher, the incentive climbs to $5,300, assuming the same purchase price. Larger systems however cost more money upfront, she said, which increases the federal tax credit in turn.

Companies like Revision Energy have set out to explain to potential customers what the rebates can mean for them. In one scenario, the company says a typical residential project involving 2 flat plate collectors that produce around 18.25MMBTU and cost $10,500 can mean an incentive package that adds up to $5,750.

There is, however, a flip side to New Hampshire's move to increase the amount of the individual rebate: it lowered the number of slots to about 248, meaning that folks wanting to take advantage should hurry in order to get the $2,000 federal chunk. The state portion of the rebate will likely continue even when the federal money runs out.

Epsen says that the PUC's new rebate structure has increased interest. The commission has processed 133 applications out of which 112 qualified for the $2,000 federal rebate.

In order to receive the requisite $2000 federal rebate, Epsen said, applications must be processed and invoices issued before February of 2012.

More on federal credit

The 30 percent federal tax credit — established by Congress in 2005 and labeled the Residential Renewable Energy Tax Credit — was capped at $2,000 for sun-powered energy systems. But that cap has been removed. So, when calculating the costs at tax time, you can include the not only your new system's equipment costs but also labor. And you can carry the credit forward into other tax years too.

Jim Gamble, owner of GreenSource Energy Solutions Solar Store in Concord, argues that customers should hurry because the funding history of the Renewable Energy Fund is inconsistent largely because it depends on utility payments under New Hampshire's Renewable Portfolio standard.

"We saw how quickly the funds dried up for the residential solar electric rebate last year," said Gamble.

Sarah Brown, president of Green Alliance, an organization that promotes environmentally responsible businesses, agrees.

"Everyone is very concerned about what the new Republican state leadership will do in terms of axing state incentives," she said. "They have made it clear that they are looking to do that."

Brown said several New Hampshire and Maine solar companies are beginning to offer unique financing options to spread initial costs of getting a solar system up and running.

Her group works with Dover-based Seacoast Energy Alternatives (SEA) Revolution Energy, as well as Concord-based Green Source Energy Solutions, companies she said are working to take the "initial financial pain out of what is a long-term cost saver."

She said that some area companies, for example, are teaming with mortgage and loan companies to make it so that a new solar system is seen as a home equity investment by a lender.

"The major hurdle for most businesses or residences considering solar is the initial up-front cost," said Brown. "So of course rebates help reduce this risk and the financing is like the icing on the cake.

"Combining rebates, tax credits and financing is the magic triangle that is really going to put solar on the map for the entire Northeast."

SOURCE: http://www.seacoastonline.com/apps/pbcs.dll/article?AID=/20110131/BIZ/101310306/-1/NEWSMAP

Massachusetts Starts Solar Rebate Program

Massachusetts is unveiling a rebate program designed to help residents pay for solar hot water projects.

Starting in February, the Massachusetts Clean Energy Center will begin accepting applications for a pilot version of the program which officials hope will encourage more homeowners to adopt solar thermal water heating technology.

Rebates for Massachusetts residents who qualify will be awarded through a non-competitive application process.

Solar hot water systems generate heat from sunlight to make hot water.

The roof-mounted solar collectors for hot water systems look similar to solar photovoltaic panels, which generate electricity rather than hot water.

A solar hot water system can provide up to 75 percent of total household hot water demand.

SOURCE

Velux Installs 60 Solar Water Heaters

On average, water heating is the second largest energy expenditure behind heating and cooling, according to information on the Energy Star website. Folks spend anywhere from $400-$600 per year on water heating, so it's a good area to scrutinize when trying to save energy at home. In South Carolina, thanks to a grant from the state energy office, 60 homes received shiny, new Velux solar water heating systems to showcase the benefits of this technology.

Southern Energy Management, a certified B corporation (SEM), partnered with Velux to install the systems at a rate of one per day. One system recipient, Ken Newell, said, "anything that can save money is a real godsend. I'm going to be very interested to see my power bill," according to a press release.

His power bill will certainly fall. The average water-heating bill drops about 50-80% upon the installation of a solar water heater, according to the Department of Energy.

Central Electric Power Cooperative, Inc. (CEPCI) will monitor 25 installations for a year to track how much solar hot water is produced and how much electricity is saved. CEPCI will then use that information to help local customers understand the potential energy savings that can be captured with solar water heating.

In support of the economic proposition, there is a 30% federal tax credit for the purchase and installation of qualifying solar water heating systems placed in service through the end of 2016. On top of that, there may be state and local incentives that make these systems even more financially attractive.

SOURCE

Solar Water Heater Facility Opens

A R40million solar water heater manufacturer – with strong Taiwanese links – was recently launched at the East London Industrial Development Zone (Elidz).

Matla Solar Water Heating (SWH) is the first renewable energy sector investor to locate in the IDZ, and the first fully integrated mass production manufacturing plant for both domestic and industrial solar water heaters in South Africa.

“The opening of Matla is a major milestone for the Eastern Cape province’s vision to position itself as a prime location for renewable energy sector investment,” IDZ spokesperson Ayanda Ramncwana said yesterday.

The facility is set to provide between 80 and 110 jobs within a year. The project is funded partly by Matla Thermal Holdings – a Taiwanese investment consortium led by Funland Industrial Co – and the Eastern Cape Development Corporation (ECDC).

The ECDC holds 15 percent equity in the firm, Matla Thermal Holding holds 53 percent and Funland Industrial Co 32percent.

The Funland Industrial consortium includes Funland Industrial Co, Tz-Jeng Energy Technology, and Ming Yang Solar Energy. They have been producing high pressure solar water heaters in Taiwan over the past 25 years, and will be sharing their expertise and knowledge in the industry at the IDZ facility.

“Our market research noted that there are a number of small scale manufacturers in South Africa.

“With the technology and expertise we have based on our current partnerships, we will be able to produce on a large scale locally which will lower the costs for customers,” said Matla SWH general manager Andy Bin-Chi Lu.

“The main target market for us initially is industrial users such as mining sector change rooms, student residences, apartment buildings and hospitals.”

The industrial/commercial solar water heater market is estimated by Matla SWH to be worth around R4billion, representing a maximum of 1000MW of peak electrical demand to be reduced.

IDZ business development executive manager Tembela Zweni said the attraction of Matla SWH in the zone was part of the zone’s renewable sector strategy.

“We are striving to operate a world-class industrial park without costing the earth; and the launch of Matla Solar is a giant step towards achieving the goal of operating a green IDZ,” said Zweni.

Solar Thermal Systems Gain Popularity

Solar hot water is getting a new day in the sun.

While most of the recent publicity has focused on its higher-tech sister, photovoltaic production of electricity, the solar thermal business is also growing.

"Solar thermal" means liquid is heated by the sun's rays and then used in homes, businesses or institutions. Most commonly, it produces what engineers call "domestic hot water," or what comes out of the hot water faucet.

But it can also be used in some cases for heating the air in a building, primarily through radiant floor systems. Another approach is solar walls, which involve using the sun to heat exterior surfaces and capturing the warmed air to supplement the heating systems.

The basic technology is an old one and fairly simple, said Ron Kamen, who is head of sales and senior vice president for EarthKind Solar in Lake Katrine and who also serves as president of the industry group the New York Solar Energy Industries Association.

The hot water approach is easily adaptable to home use and not nearly as expensive as the photovoltaic approach, Kamen said, though he advocates and handles both.

"There's 10 times as much solar hot water installed as solar electric," he said. "Everyone else in the world pretty much does it. It's a very simple technology, very straightforward. It's the most cost-effective method."

"There's a tremendous need for residential. Hot water is about one-third of the average family fuel bill," Kamen said.

Among the convinced are Robin and Rashmi Sen, both architects with a practice in New York. They have designed and are building a house and studio in Salt Point where solar hot water is used to supplement both domestic hot water and space heating.

They got into green design in some Brooklyn projects, Robin Sen explained, and then brought the approach home.

"We wanted to put in as much as we could in terms of using the least amount of fossil fuels," he said. The house burns no fuels on site, but uses electricity. It has a hybrid heating system that consists of a geothermal heating-cooling system and a solar hot water array ground-mounted near the house.

The house has a ceramic floor that becomes a heater when the solar-heated water is run through it. Sen said that the solar water panels can heat the house adequately when outside temperature drops to as low as 50 degrees. Lower than that, and the geothermal kicks in to help.

Interest is spreading. Contractor Joseph Malcarne has expanded his business into the installation of these units and put some atop his house in Staatsburg.

The solar association list of members is growing, as contractors from various trades get interested in offering such work.

Alteris Renewables has opened a two-person office with hopes of growth at TechCity, the same Lake Katrine facility that houses EarthKind and a growing number of solar-related businesses.

A major solar hot water system was dedicated Monday at Benedictine Hospital in Kingston, for which EarthKind was the source.

It was part of a $428,000 federally funded solar technology and energy efficiency project at the Kingston, Benedictine and Margaretville campuses of the Health Care Alliance. Rep. Maurice Hinchey, instrumental in obtaining the funds, said it was aimed at energy efficiency and cutting carbon emissions.

The Solar Energy Consortium and engineering students at the State University of New York New Paltz assisted.

Environmental consciousness is one stimulus for the solar movement, as is federal and state aid. But the economy hasn't been one.

Elaine Lacy, marketing director for EarthKind , said the slow economy has been felt.

"I think more people are hesitant," she said. "But people are still interested, still calling."

The savings in energy costs are a key selling point. The recession put soaring fuel costs on a holiday, but in the long term, the economics favor alternative sources, Kamen said.

He said fuel prices would rise, and cited the need for energy independence. And as for oil, "It eventually is going to run out. It's just a question of time."

Perhaps the biggest hurdle to jump is the capital cost of the systems. A two-panel solar hot water rig and its associated gear can cost a homeowner about $8,000 to $10,000 and would save about half to two-thirds of the operating costs of getting domestic hot water.

But that upfront cost can soon be offset not only by the savings, but by the hefty federal and state tax credits that can be claimed on the next tax return.

A credit is a dollar-for-dollar savings off one's tax liability. The federal credit is 30 percent. So, for example, a $10,000 system cost brings a $3,000 credit. The state offers a 25 percent credit, which would be good for $2,500. Combined, the credits are $5,500, cutting the homeowner's final cost to $4,500 in this example.

The cost recovery through savings is fastest for people who heat their water with electricity, Kamen said. The second-fastest is oil and the longest recovery is with natural gas.

The final cost recovery may come when the house is sold and fetches a higher price because its energy efficiency is a selling point.

Kamen said solar hot water for heating air is an emerging field. It's being done, as Sen's case shows, but mostly in new construction. Solar hot water does not get up to the range needed for baseboard heaters, for example. But engineers are finding ways to integrate solar hot water with other techniques in combination systems that use solar as a pre-heater and some other gear to handle the rest of the temperature rise.

An obvious shortcoming is that solar is weakest when you need it most, in the winter, and strongest when you need it least, in the summer. A system sized to perform well in winter will produce waste heat all summer. Kamen said some installations use that heat for swimming pools and hot tubs.

Research is aimed at finding ways to turn the excess heat into energy that can then run cooling systems. It's been done, but not yet in a cost-effective way, Kamen said. These sun-driven coolers will most likely be used in commercial buildings first.

Straight solar air is getting used, too. At the Army's Fort Drum in upstate New York there is what's claimed to be the nation's largest installation of solar walls.

There, 50 SolarWall skins have been installed on 27 buildings to collect hot air that is then pumped inside to handle part of the heating. The company says tests on one system saved about $1,000 a month in natural gas costs.

The New York Solar Thermal Consortium, a group of institutions and businesses, has begun drawing up a "Solar Thermal Road Map for New York State" with the aim of growing from about 500 systems now to about 20,000 in a few years and half a million by 2020. That would create 20,000 jobs, too, Kamen said.

SOURCE

Unity College Bestows a Solar Gift

A world leader in solar energy came to Unity College Thursday to accept one of President Jimmy Carter's solar panels as a donation to his Solar Science and Technology Museum in China's Shandong Province.

A world leader in solar energy came to Unity College Thursday to accept one of President Jimmy Carter's solar panels as a donation to his Solar Science and Technology Museum in China's Shandong Province.

Huang Ming, center, chairman of Himin Solar Energy Group of China, acknowledges applause after accepting a solar panel donated to his Solar Science and Technology Museum from Unity College during a presentation on Thursday in Unity. At left is Dana Connors, president of the Maine Chamber of Commerce, and Unity College President Mitchell Thomashow.

Huang Ming, chairman and founder of Himin Solar Energy Group, said in exchange for the panel he'd like to offer the White House a state-of-the-art solar water heating system made by his company.

The gift of the solar panel, Ming said, marked the beginning of a relationship between his company and the college -- and progressive cooperation between China and the U.S.

Flying into New York's John F. Kennedy International Airport, he said he only spotted a couple of rooftops with solar heating systems. That's something he'd like to help change.

"Change is necessary. It's possible. It's easy," he said. "Change our behavior, change our activities, change our minds, and we will change the world."

Unity officially handed off the solar panel to Ming around noon Thursday in the college's Centre for Performing Arts. The event was the culmination of a months-long conversation among Unity officials, Ming and his friend Julian Chen, a physics professor at Columbia University.

Chen was researching solar energy online and learned that Unity College had acquired the solar panels that Carter had had installed on the White House in 1979. He knew that Ming would want one.

In fact, when Chen told Ming about the panels, Ming said he'd pay anything to get one for his museum. Much to the men's surprise, the college offered to give him one for free, Chen said.

After the solar panels were removed from the White House during the Reagan administration, Unity installed them in its cafeteria, where they heated water for 12 years. The college recently donated one of them to the Smithsonian Institution in Washington, D.C.

Last month, a documentary about the panels, called "A Road Not Taken," was screened at the Maine International Film Festival in Waterville.

At the event Thursday, Ming talked about his company's efforts to promote the use of solar energy.

Himin Solar, the world's largest manufacturer of solar water heaters, produces 3 million water heaters annually and was a driving force behind the creation of China's Solar Valley, a massive development in the city of Dezhou in Shandong Province that maximizes the use of solar energy.

Solar Valley is home to Himin's headquarters, called the Sun-Moon Mansion, as well as the Solar Science and Technology Museum.

Ming said the Carter solar panel, which he'll show with pictures displaying its historical significance, will be his second favorite artifact in the museum. His favorite still will be a 3,000-year-old mirror that used the sun to start fires.

Unity College President Mitchell Thomashow said Thursday that Ming's visit was "the highest possible compliment."

The honor came on the heels of another significant achievement, Thomashow said. On Monday, The Princeton Review named Unity to its Green Rating Honor Roll -- a list of the 18 most environmentally-friendly higher-learning institutions, which also includes Harvard College, Yale University and College of the Atlantic in Bar Harbor.

Mick Womersley, a professor and director of sustainability at the college, agreed it was significant to have someone of Ming's stature visit the school.

"It's a bit of recognition for the hard work we've done," he said.

Huang Ming, center, chairman of Himin Solar Energy Group of China, acknowledges applause after accepting a solar panel donated to his Solar Science and Technology Museum from Unity College during a presentation on Thursday in Unity. At left is Dana Connors, president of the Maine Chamber of Commerce, and Unity College President Mitchell Thomashow.

Huang Ming, chairman and founder of Himin Solar Energy Group, said in exchange for the panel he'd like to offer the White House a state-of-the-art solar water heating system made by his company.

The gift of the solar panel, Ming said, marked the beginning of a relationship between his company and the college -- and progressive cooperation between China and the U.S.

Flying into New York's John F. Kennedy International Airport, he said he only spotted a couple of rooftops with solar heating systems. That's something he'd like to help change.

"Change is necessary. It's possible. It's easy," he said. "Change our behavior, change our activities, change our minds, and we will change the world."

Unity officially handed off the solar panel to Ming around noon Thursday in the college's Centre for Performing Arts. The event was the culmination of a months-long conversation among Unity officials, Ming and his friend Julian Chen, a physics professor at Columbia University.

Chen was researching solar energy online and learned that Unity College had acquired the solar panels that Carter had had installed on the White House in 1979. He knew that Ming would want one.

In fact, when Chen told Ming about the panels, Ming said he'd pay anything to get one for his museum. Much to the men's surprise, the college offered to give him one for free, Chen said.

After the solar panels were removed from the White House during the Reagan administration, Unity installed them in its cafeteria, where they heated water for 12 years. The college recently donated one of them to the Smithsonian Institution in Washington, D.C.

Last month, a documentary about the panels, called "A Road Not Taken," was screened at the Maine International Film Festival in Waterville.

At the event Thursday, Ming talked about his company's efforts to promote the use of solar energy.

Himin Solar, the world's largest manufacturer of solar water heaters, produces 3 million water heaters annually and was a driving force behind the creation of China's Solar Valley, a massive development in the city of Dezhou in Shandong Province that maximizes the use of solar energy.

Solar Valley is home to Himin's headquarters, called the Sun-Moon Mansion, as well as the Solar Science and Technology Museum.

Ming said the Carter solar panel, which he'll show with pictures displaying its historical significance, will be his second favorite artifact in the museum. His favorite still will be a 3,000-year-old mirror that used the sun to start fires.

Unity College President Mitchell Thomashow said Thursday that Ming's visit was "the highest possible compliment."

The honor came on the heels of another significant achievement, Thomashow said. On Monday, The Princeton Review named Unity to its Green Rating Honor Roll -- a list of the 18 most environmentally-friendly higher-learning institutions, which also includes Harvard College, Yale University and College of the Atlantic in Bar Harbor.

Mick Womersley, a professor and director of sustainability at the college, agreed it was significant to have someone of Ming's stature visit the school.

"It's a bit of recognition for the hard work we've done," he said.

SOURCE

Solar Heating Installed in Forest Preserve Restrooms

The Forest Preserve District of DuPage County recently completed the installation of five solar-thermal hot-water systems.

Sun-heated water is flowing at public restrooms at three forest preserves, Springbrook Prairie in Naperville, Hidden Lake in Downers Grove and Spring Creek Reservoir in Bloomingdale.

Solar-thermal systems are also at work at the headquarters building at Danada Forest Preserve in Wheaton and the structural maintenance facility at Blackwell Forest Preserve in West Chicago.

The solar-thermal systems work in conjunction with conventional natural gas or electric hot-water heaters, which were already in use. Solar panels mounted on the buildings' roofs preheat water using energy from the sun, reducing or at times eliminating the use of natural gas or electricity. Through reduced energy costs, the district's return on investment is about eight to 10 years.

"Even on cloudy days and through cold weather in winter, solar energy can produce hot water," said Jason Berger of the district's structural maintenance department. "The systems are designed to last at least 20 years with little to no maintenance, so the long-term savings of both utility costs and conventional energy resources will be beneficial."

A grant from the Illinois Clean Energy Community Foundation paid for 25 percent of the costs, and a rebate from the Illinois Department of Commerce and Economic Opportunity's Solar and Wind Energy Rebate Program funded 30 percent.

SOURCE

Habitat for Humanity Goes Green

Habitat for Humanity International is dedicated to the cause of eliminating poverty housing. Since its founding in 1976, Habitat has built more than 300,000 houses worldwide, providing simple, decent and affordable shelter for more than 1.5 million people.

While it's known for building quality homes for low income buyers who might not otherwise be able to afford a home, once the keys are handed over there are no guarantees that the new residents will be able to afford rising utility costs. Habitat acknowledges this challenge and is now building with green in mind.

A select group of volunteers dubbed the "Green Team" work nationwide with Habitat for Humanity to build more energy efficient homes for residents. Whether it be extra insulation in the attic or solar powered hot water heaters, Habitat for humanity is making a move to more sustainable construction and hopefully this is a trend that will continue for all new home construction.

Last year, Habitat for Humanity announced plans to build 5,000 green homes around the country for low-income families. These homes, would be built over five years, and would meet EnergyStar guidelines or other green building standards, like LEED. The project expands on a pilot program and is being done in conjunction with the Home Depot Foundation.

Although green building carriers higher upfront costs, approximately $5,000 for an EnergyStar and LEED certified home, due to the extra materials as well as the certification process itself and extra training, it's worth it in the long run. Increasing the typical Habitat home price tag of $75,000 by a mere five grand allows families to enjoy a rapid payback in terms of lower energy bills. From new energy-efficient water heaters and weather stripping to programmable thermostats and low-flow toilets and solar panels, families see immediate savings in their monthly utility bills. Knowing a family can afford to maintain and live in these new homes for years to come means so much to these new homeowners and to these communities.

Other green initiatives from Habitat for Humanity include a new development in Oakland, California. Here, Habitat has converted a brownfield into several green homes as part of its ongoing EastBay Project. With help from Pacific Gas & Electric (PG&E) and a slew of volunteers, Habitat built a 54-home development of affordable housing for low-income homeowners. The development site, a former battery salvage yard, was labeled a “blighted property” by the EPA and California’s Department of Toxic Substances.

While roughly 300,000 cubic yards of soil had to be removed and replaced, the effort was well worth it for the new residents. In December of 2009, after dedicating their time and energy to helping build their homes, as required by Habitat, the excited homeowners were handed the keys to their new green homes.

Some features these green homes in EasyBay include a passive solar design which eliminates the need for air conditioning. Homes with a basic passive solar design are elongated on an east-west axis, have south-facing rooms and windows, incorporate foliage for shade, use less space on the north side, especially for rooms that require the most light and heat, and have an open floor plan for optimal thermal mass.

PG&E also offered a $15,000 grant per home for the 1.8-2 kW worth of solar power panels installed on the EastBay homes, including the inverter. The estimated utility bills for these homes as a result of the passive solar design and solar electricity is a meager $9 per month for two bedroom homes and less than $15 per month for the three and four bedroom homes. The grants for the solar power panels came as part of PG&E’s Solar Habitat Program, an ongoing partnership between the utility company and Habitat for Humanity.

The solar panels installed on the East Bay Habitat homes generate nearly 300kWh of clean, renewable energy from sunlight each month, saving the families approximately $500 a year on energy costs. Each panel will also help avoid the release of more than 132,000 pounds of carbon dioxide to the atmosphere over the 30 year life of the system.

PG&E's Solar Habitat Program is a partnership between PG&E and Habitat for Humanity International to fund the full cost of solar electric systems on every Habitat built home in northern and central California. This partnership brings solar energy to families with limited incomes, to provide affordable, renewable energy to California residents.

Solar Water Heaters Mandatory in Hawaii

As of January 1, 2010, building permits on all single-family new home construction in Hawaii may not be issued for homes that do not include a solar water heating system. This legislation, SB644, was enacted in June of 2009; however, the state energy resources coordinator may be able to provide a variance for this requirement if:

• Installation is impracticable due to poor solar resource;

• Installation is cost-prohibitive based upon a life cycle cost-benefit analysis that incorporates the average residential utility bill and the cost of the new solar water heating system with a life cycle that does not exceed 15 years;

• A renewable energy technology system is substituted for use as the primary energy source for heating water; or

• A demand water heater device approved by UL is installed; provided that at least one other gas appliance is installed in the dwelling. (A "demand water heater" means a gas-tankless instantaneous water heater that provides hot water only as it is needed.)

While the legislation is already in effect, the Hawaii Public Utilities Commission must still adopt specifications for the required performance, materials, components, durability, longevity, proper sizing, installation and quality of solar water heaters.

Already, even before the impact of this new legislation is felt, there are over 65,000 solar water heaters in use in Hawaii today, including thousands on the Big Island. In fact, Hawaii ranks number one in the nation when it comes to using energy from the sun to heat water.

With an eye toward the future, Hawaii law makers understand that conventional water heaters are typically the largest electricity consumer in the average household, gobbling up nearly 40% of consumption. Hawaii's move to force solar heating is a big step for a state that relies heavily on imported fossil fuels for 90% of its supply. This bill has been a long time coming - when the legislation was first introduced five years ago, a barrel of oil cost just $40. Since then, the price has more than tripled.

Overall, solar water heating may save about $6 to $12 or more per person per month when replacing a standard electric resistance water heater. The savings, of course, will vary by household based in part on each person's hot water usage.

Using solar water heating can help keep electric rates down by also reducing electricity demand during the peak evening times from 5 p.m. to 9 p.m. when people often use hot water for washing dishes, taking showers, and so forth. To meet this evening peak demand, less efficient electricity generation units must be brought on-line by the power companies. These less efficient units cost more to run and this increase in cost is passed on to consumers.

Not surprisingly, builders and developers were against the new bill, saying it would add too much to the cost of new home constructions. Another surprising opponent was the Hawaii Solar Energy Association. Ron Richmond, with the association, said in an interview with the Star Bulletin, the new legislation would cost home buyers about $2,100 more to have the solar water heaters installed. The average solar water heater, according to the article, currently costs about $5,250, before rebates.

The length of time required to recoup your original investment (payback) will vary widely and depend on whether the purchase is paid for outright or financed and how much energy (electricity, gas, etc.) is saved. Simple payback is the length of time required to recover your investment through reduced or avoided costs. You can expect a shorter payback in areas that have higher energy costs, where the family uses a moderate to large amount of hot water per person, and for homes with more occupants. Finance charges will also lengthen the payback period.

While this new program may make some new homeowners balk at first, there are additional benefits when the cost of a solar water heating system is included in the mortgage for a home purchase. The interest rates are usually lower than on a short-term loan. In addition, the small additional increase in the monthly mortgage payment may be more than made up for in reduced energy costs (electricity or gas).

In the short run, those purchasing new homes in Hawaii may feel a pinch in their wallet upfront in having to install a solar hot water heater; however, over a short period of time, these new homeowners will easily recoup their investment. And, more importantly, by diversifying the State of Hawaii's mix of energy resources by using more renewable energy, such as solar, helps to make Hawaii less dependent on non-renewable energy sources and, in my opinion, a Greener place to live.

Solar Water Heaters = GREEN

An ENERGY STAR qualified solar water heating system can cut your annual hot water costs in half, and is generally designed for use with an electric or gas back-up water heater. Demonstrate your environmental leadership by voting with your wallet for renewable energy solutions. Purchase an ENERGY STAR qualified solar water heater for your home and enjoy these benefits:

Save money. By using sunshine to heat or preheat your water, you can cut your water heating bill in half. This means you can save $190 annually if you combine solar with a backup gas-storage water heater instead of using the gas water heater alone. If you have an electric tank water heater for back-up, you'll save about $250 each year on electricity bills. Large families with greater hot water needs can save even more.

Invest in a better environment. Water heated by the sun just feels better. The purchase of a solar system can take about 10 years to pay for itself, but by taking advantage of Federal tax credits you can recoup the price premium more quickly. In the meantime, your investment will pay dividends for the environment. ENERGY STAR qualified solar water heaters can cut your carbon dioxide emissions in half. Installing a qualified solar water heater will reduce the load of your electric water heater by almost 2,500 kWh per year, preventing 4,000 pounds of carbon dioxide from entering the atmosphere annually. This is the equivalent of not driving your car for four months every year!

Long lifetime. The average life expectancy of qualified solar water heating systems is 20 years, much longer than standard gas or electric storage water heaters.

SOURCE

What is a Solar Water Tempering Valve?

Tempering Valve
AKA: mixing valve

On a sunny day, the water in your collectors can reach scalding temperatures. A tempering valve can save you from a 160°F (70°C) shower. Ouch! The tempering valve goes at the very end of the chain, right after the backup water and before the faucet. If the water coming out of the backup heater is too hot, the tempering valve opens to mix cold water back in and prevent scalding. The temperature of the hot water can be set by the user on most valves. For instance, a popular valve allows a temperature setting between 120°F and 160°F (49°C-71°C).

What is a Solar Water Backup Water Heater?

Backup Water Heater
AKA: natural gas, propane, electric, or wood water heater

The backup water heater ensures that hot water is at the tap whether the sun shines or not. On a sunny, hot day, if the sun has preheated the water to 140°F (60°C) or more, the backup water heater uses no energy at all because the solar preheat temperature is greater than the typical 120°F (49°C) thermostat setting. On a day when the solar preheat is 85°F (29°C), the backup heater boosts the temperature the remaining 35°F (19°C). Since incoming cold-water temperatures are at ground temperature (usually about 50°F; 10°C), 85°F represents 50 percent of the energy needed to bring the water from 50°F to 120°F.

Not all backup water heaters use a tank. Keeping a tank of water warm between uses can account for 15 percent or more of the total energy expended for hot water. Tankless water heaters eliminate this standby loss. Solar hot water systems and tankless water heaters are a winning combination. If you´re in Seattle, for instance, and can reduce your water heating cost by 60 percent using solar energy, and save another 15 percent by going tankless, this results in a 75 percent total savings. The household that used to spend $300 per year to heat water now only spends $75. In sunnier climates, this number can approach zero. However, not all tankless heaters can be used as a backup heater for solar. Check with the manufacturer.

What is a Solar Water Isolation Valve?

Isolation Valve
AKA: solar bypass

An isolation valve should be a part of every solar water heater to isolate the solar tank in case of a problem, while still allowing the backup water heater to remain in service. The isolation valve is a manual valve or valves placed in both the incoming and outgoing potable water lines to the solar tank. It can be a three-valve configuration, or a three-port and two-port valve. Manually turning the valve or valves will place the solar tank "on line" or "off line." It works by directing the flow either through or past the solar tank. These valves can also be plumbed to bypass the backup gas or electric water heater, allowing them to be turned off (eliminating standby heat loss) during the seasons when the SHW system can supply 100 percent of the household´s hot water.

What are Solar Water Controls?

Controls
AKA: differential controls, PV module

In active systems using pumps, whenever the collector is hotter than the storage tank, the pump should be on and the system circulating. When the tank is hotter than the collector, the pump should be off. This function is performed by either a differential thermostat control system or the use of a PV-powered pump. The differential thermostat controller compares heat sensor readings from the storage tank and collectors and switches the pump accordingly.

With a PV-powered pump, a solar-electric panel is connected directly to the pump. It´s a simple setup—when the sun comes out, the pump comes on. The brighter the sun, the faster it pumps. Controls are not needed in batch heater systems, where energy is moved by simple water pressure, or in thermosyphon systems, where energy is moved naturally by heat rising.

What is a Solar Water Expansion Tank?

Closed-loop systems require an expansion tank. An expansion tank has a chamber in which air is locked inside a bladder or diaphragm. It screws into standard 1/2-inch or 3/4-inch threaded plumbing fittings. When pipes are filled with heat-transfer fluid (water and glycol) and the operating pressure of the system is set, the fluid will occupy a given volume based on the temperature. As the fluid is heated by the sun, it expands. This is where the expansion tank is critical. Without it, something would blow!

The expansion tank allows the fluid to safely expand by compressing the air in the chamber. The size of the expansion tank needed depends on the total volume of fluid, which is determined by the number and size of collectors, and the length and diameter of the pipes in the solar loop.

In most cases, a total of 3 to 6 gallons (11-23 l) of fluid is in a solar loop. A #15 (2 gal; 7.6 l) expansion tank is usually adequate. It never hurts to go larger, especially for systems with more than 60 square feet (5.6 m2) of collectors. A #30 has twice the expansion capability. With the proper expansion tank in place, the fluid can go from 0 to 200°F (-18-93°C) with the pressure in the solar loop remaining the same.

What is a Solar Water Heat Exchanger?

Heat exchangers are used in closed-loop solar hot water systems. They enable the transfer of heat from one fluid to another without the two mixing. Internal heat exchangers are inside the tank and not visible. They can be as simple as a coil of pipe resting in the bottom of the tank, or wrapped around the outside beneath the insulation and cover. As the heated fluid from the solar collector travels through the coil, the heat is passed from the hotter fluid to the cooler potable water.

An external heat exchanger is usually a pipe within a pipe. The solar fluid and potable water flow counter to one another, and heat is transferred within the heat exchanger pipe. Fluid may be moved with pumps, thermosyphoning, or a combination of the two.

What is a Solar Water Pump?

Water Pump
AKA: circulating pump, circulator

Pumps are used in active systems, but are not required in batch or thermosyphon systems. They circulate water or antifreeze between the solar collector and the storage tank. The right pump for the job depends on the size of the system and the distance and height between the collector(s) and the storage tank. AC pumps plug into a wall outlet while DC pumps are powered from a DC source, such as a photovoltaic panel. Good pumps can last as long as 20 years with heavy use.

What is a Solar Storage Tank?

Solar Storage Tank
AKA: solar water tank, solar tank

A solar water tank is an insulated water storage tank. Cold water that used to go directly to your conventional water heater enters the solar tank and solar-heated water exits. In closed-loop systems, the water is heated by contact with a coil of pipe containing the water or antifreeze that circulates through the collectors. In open-loop systems, the potable water is directly circulated through the collectors.

The preheated solar water is then plumbed back to the cold side of your existing heater, which now functions as a backup. Whenever hot water is turned on in the house, preheated solar hot water is moved from the solar tank to the backup heater.