Some Assembly Required?

August 22, 2012

Could the IKEA concept of “offering a wide range of well designed, functional home furnishing products at prices so low that as many people as possible will be able to afford them” be expanded to include solar and wind energy?

With IKEA plugging into solar power for almost all of its U.S. buildings, could IKEA-brand solar panels for your home be far behind? Of, course some assembly would be required. And there would be an Allen wrench.

Just thinking.

PVs, Troughs and Towers – Electricity from the Sun

April 21, 2011

When we think of solar powered electricity, the image that usually comes to mind is one of solar panels on the roof of a building. Solar panels consist of many connected photovoltaic (PV) cells which are made mostly of silicon with other compounds. When light energy strikes a PV cell, some of the energy is absorbed, freeing electrons which then form an electric current.

Solar panels are most often used in small applications, such as providing electricity for a house or similar sized building. However, there are now solar parks, similar to wind farms, where large arrays of solar panels provide power to electricity consumers. The largest such solar park is the 80 megawatt Sarnia Solar Project, pictured here, in Sarnia, Ontario.

Image: Enbridge

The overall efficiency, from panel to grid is about 15 per cent.

The other way to produce solar electricity is through a process known as concentrated solar power. Lenses or mirrors are used to focus sunlight on a small area to heat a liquid which flows through a heat exchanger creating steam to run a turbine. The two most common forms of concentrated solar power are parabolic troughs and solar power towers.

Parabolic troughs are, as the name suggests, troughs with reflecting surfaces in the shape of a parabola. The suns rays are focused by the parabola onto a pipe running the length of the trough. A synthetic oil in the pipe heats to 350 °C and is used to make the steam that runs the turbine. Efficiency is similar to that of PV cells.

Solar power towers consist of a field of mirrors which concentrate light on a receiver located atop a tower at one end of the array. The receiver heats a fluid that provides the heat for steam generation. Overall efficiency is slightly better than that for parabolic troughs.

When solar cells head off into the sunset

October 26, 2010

Nothing lasts forever, even renewable power sources. Sure, we’ve got a few  billion years before we have to worry about the Earth being consumed by the sun when it becomes a red giant (yep, that’s going to happen), but in the shorter term the generation technology we use to harness the elements has a shelf life. So, what happens to solar cells when they die?

Devices installed in the early ’90s are nearing the end of their 25-year lifespan. And given that many of these devices contain rare and toxic metals, we have strong incentives to do more than just throw them away. Recycling our expired energy devices doesn’t just keep toxic materials out of landfills, it also maintains our limited supplies of rare metals.

At Arizona State University in Tempe, researcher Jun-Ki Choi has calculated how many solar cell disposal sites a country or region should have (in the study, Germany was used as the model), and where they should be located.

Waste disposal is always an essential question in energy production. It’s no coincidence that China, the source of 97 per cent of the world’s neodymium, dysprosium and other rare earth elements, was also the place where toxic silicon tetrachloride produced during photovoltaic manufacture had been dumped onto farmland. As our energy generation evolves, our waste disposal technology will have to evolve as well. It would be too ironic if, while trying to reduce emissions, we ended up producing landfills full of toxic materials.

Via New Scientist

Urchin power!

September 29, 2010

Image: EMPA

Can you imagine using polystyrene spheres as a sort of scaffolding to create three-dimensional nanostructures of semiconducting zinc oxide on various substrates? Probably not! And that’s why you’ll never be a nanostructure researcher developing innovative ways to expand the surface area for solar panels.

Just kidding, nobody actually expects you to know what polystyrene spheres are, let alone how they could be applied to improve the potential for surfaces on photovoltaic panels. But as this extremely enthusiastic release from the Swiss Federal Laboratories for Materials Science and Technology (EMPA) explains, the creation of a microscopic polystyrene balls with protruding zinc oxide nanowire “spines” could have important benefits for solar panels. In short, that means that rather than a solid sheet, the PV panel’s surface could become an interlocked series of balls, each of which would add a relatively larger amount of surface area. More surface area means a greater chance to absorb sunlight, which means more bang for your PV buck.

And our solar panels aren’t the only ones using their surface area to absorb sunlight. Across the country, there are distinct pockets of “photovoltaic potential” ranging from 800 kilowatt-hours to more than 1,400. Of course, the vast majority of our country isn’t covered in solar panels, but with lightweight technologies like polystyrene spheres coming down the pike, it won’t be long until we’re taking better advantage of our available solar energy.

Via EurkAlert!

A little fit over microFIT

July 22, 2010

The Globe and Mail recently profiled a rising wave of resentment over a change in Ontario’s otherwise popular feed-in-tariff (FIT) program. A quiet change to the regime on July 2 reduced the rate paid to solar producers from 80.2 cents to 58.8 cents per kilowatt hour for ground-mounted solar photovoltaic, which has some producers up in arms. Solar PV hadn’t previously been separated into two distinct categories (roof- and ground-mounted).

The change won’t affect the rate being paid to existing producers, who sign a contract for at least 20 years guaranteeing a preferable rate, but it would affect those who are just beginning the process of singing up. That’s inflamed tempers faster than an efficient solar heating panel.

The Globe’s article quotes one would-be producer, John Verway of Copperhill Alternate Energy, in an open letter saying that the change is “a misguided and miscalculated change” that could “destroy the progress so many have made so far.”.

The guaranteed, relatively high rate being paid for renewable power is a cornerstone of Ontario’s Green Energy Act, designed to increase the production of renewable power and associated industries. Under the FIT program, the Ontario Power Authority guarantees that renewable power producers will be paid a subsidized rate in the long term. In the case of the microFIT program, these projects have to generate less than 10 kilowatts.

But while the contracts are meant to guarantee funding in the long term, the change to the payment schedule is happening immediately.

According to the announcement of the change, anyone wanting to comment on the change has until August 2. A subsequent announcement also outlines the government’s rationale for the change, and once the deadline has passed, any complaints made afterward will unfortunately just be hot air. And under FIT, wind power uses a different payment schedule.

Via The Globe and Mail

Where The Sun Shines

June 29, 2010

The Drake Landing Solar Community in Okotoks, Alberta met an important milestone last month, keeping its residents toasty almost exclusively with the aid of the sun. After three years, the project has successfully reached its goal of providing 80 per cent of the homes’ heating from an array of 800 solar panels on garage roofs around the community.

With new homes being increasingly built to take advantage of solar heating, either through active sources like solar panels or passive sources like strategically placed windows, successes like Okotoks’s go to show that it’s possible to take charge of our energy use beginning where we live.

Started on June 21, 2007 — the day of the summer solstice — The Drake Landing Solar Community certainly experienced hiccups along the way. In the project’s first two years, it missed its annual targets by 10 to 15 per cent. But now, according to the community’s website, it’s currently on track to reach 90 per cent of its users’ heating needs by the project’s fifth year.

Southern Alberta is in a particularly well located to take advantage of solar energy, with between 1,200 and 1,300 potential kilowatt hours available . In fact, a band of high potential runs throughout southern Alberta, Saskatchewan and Manitoba, providing a natural fit for residential and large scale solar projects.

And it’s not just Alberta that’s showing the country how much potential lies in solar energy. Ontario Solar Thermal Heating Incentive Program (OSTHI) provides funding to encourage the installation of solar heating, just as Saskatchewan’s Solar Heating Initiative for Today (SHIFT) encourages a variety of consumers, from residential to municipal, to do the same.

With successes like Okotoks paving the way, solar heating definitely has a bright future.

Via Calgary Herald

Powering the Pope

October 7, 2009

popemobileThe Pope is looking to the sky and a “higher power.”

That may not sound unusual, but the power is high because it comes from the sky. Confused yet? We’re referring to solar power, of course.  What did you think?

In a recent encyclical about the economy, the Pope had a friendly reminder for the people of the world; “the environment is God’s gift to everyone and must not be squandered.” The Pope voiced concerns about certain states hoarding non-renewable energy resources, “a grave obstacle to development in poor countries.”

The Pope has spoken about energy before, but this time he went on to say “it should be added that at present it is possible to achieve improved energy efficiency while at the same time encouraging research into alternative forms of energy.”

That’s not empty rhetoric. The Vatican has already installed solar panels on Nervi Hall and more recently, Paul VI Hall. The next step: to build Europe’s largest solar power plant, which will generate enough energy for all 40,000 Vatican City residents.

After becoming the first solar-powered nation in the world, the Vatican plans on eventually exporting excess solar energy to Italy. Additionally, the Vatican’s cafeteria will be hooked up to solar heating and cooling units. They’re even considering an electric Popemobile.

The project has a large price tag; $660 million to build the power plant. But as His Holiness might argue: God put the sun there for a reason.

Solar power

July 29, 2009

sandiadishsirling

Photo by Randy Montoya

You know the expression “the sky’s the limit.” With solar power, that’s literally true – and Canada has a lot of sky. It’s surprising, then, that Canada has been somewhat slow to embrace solar as a viable energy source.

There are positive signs this is changing.

Take Calgary – according to the Environment Canada, the country’s sunniest major metropolitan centre, at 333 days of sun per year. Until August 2008, residents who wished to install solar panels had to apply for development permits. That doesn’t sound too bad on the surface, but the permits cost $3,000 and approval took weeks. The lethal combination of extra cost and significant delay effectively killed not a few prospective solar projects.

Ending the permit requirement for solar panels happened concurrently with Alberta’s provincial government passing a new law. Alberta’s electrical utilities are now required to compensate customers for the surplus power they produce (from solar or any other source). Suddenly, Albertans – and especially Calgarians – found it cheaper, less time-consuming, and more rewarding to install solar panels.

That’s no mere drop in the bucket, and representative of the shifting mood and increasing opportunities for solar across the country.

As of late 2008, the solar power industry was growing annually by 30 to 40 per cent. This is a timely trend; experts say new technologies on the verge of being ready for the market are about to make solar power lighter, cheaper and more efficient.

Until fairly recently, solar powered electricity, or photovoltaic, was prohibitively expensive. It only made economic sense in remote locations where transmission and construction costs made hooking up to the grid a pricey proposition. Solar heating (also called solar thermal) was cheaper and thus much more widespread.

What makes solar power so expensive? In short, the necessary raw materials, and inefficient technology.

First, the raw materials. Whether photovoltaic or thermal, solar panels are primarily made of silicon. Silicon is costly stuff – or, at least, it used to be. A couple of years ago, The Economist famously predicted solar technology would remain expensive until the price of silicon falls. And lo, it has.

New Energy Finance, a London-based energy analysis and research firm, predicted silicon prices would fall over 70 per cent by 2015. That’s on top of the 40 per cent it fell from 2006 to 2008. This has real impact on the price of solar power. In the US, a one-watt solar cell cost $50 in 1980. It’s currently just under $3.

That would be impressive enough, even if “conventional” electricity remained cheap in Canada – but it’s not. Costs are rising across the board, just as solar is getting cheap. “Grid parity” (where solar costs the same per kilowatt hour as conventional electricity) is a term often used in green energy circles, most often in the form of misty-eyed dreaming. Suddenly, it’s just over the horizon – five years in some European markets, say experts. It’ll take longer in Canada, but if current trends continue, it will come just the same.

Second, technology. Until very recently, generating electricity from solar panels was extraordinarily inefficient. In 1984, a particular new solar energy system achieved a sunlight-to-energy efficiency rate of 29.4 per cent. In other words, more than 70 per cent of the solar heat collected was simply waste. That record rate stood for 24 years – an amazing span of time in the tech world.

In January 2008, that record finally fell. New Mexico-based Sandia National Laboratories tested its new Serial #3 solar dish, and achieved a 31.25 per cent conversion rate. While Sandia happily admits it was an extraordinarily bright and sunny day, the real story was the new solar panel design.

While the device defies quick verbal description, here’s a capsule summary. 82 mirrors are set up to create a dish shape, which has the effect of focusing the light into an intense, hot, beam. Ever watch kids fry ants with a magnifying glass? Same concept.

Electricity is generated by focusing the beam onto a receiver and engine, which is filled with hydrogen. The design is efficiency itself, as the mirrors transmit 94 per cent of the available sunlight to the engine. As the gas heats and cools, the pressure drives pistons, which drives a generator.

You might be wondering if that’s truly a big deal – we’re talking about less than two percentage points here. Well, those add up in a hurry. In a 2.5 hour test, the Sandia facility generated 26.75 kilowatts of juice. Two percentage points’ difference means half a kilowatt – or about the total energy generated by a small solar cell unit.

Improvements aren’t just coming from improvements on existing designs, though. Researchers at UC Santa Cruz have been developing a handful of techniques for nanotechnology solar cells. When tested, they delivered a higher-than-expected conversion rate. In the UK, a researcher is exploring ways to design hybrid solar cells – combining organic and inorganic conductors – which may allow for higher conversion rates.

What do these developments mean for Canada? After all, it’s a nation blessed with natural resources that already enjoys some of the world’s lowest energy costs. Canada has traditionally and continues to see solar as a contributor; part of the national energy puzzle, but not an overarching cure-all.

Currently, about 20 per cent of all Canadian energy use is residential. While installing solar cells can put a dent in energy bills, that’s about the limit. Under current costs replacing a typical furnace with a solar system would cost between $15,000 and $30,000. It would eventually pay for itself – eventually. Natural Resources Canada says a 100 per cent solar-powered home becomes a good investment after 30 to 40 years of continuous use.

That has created a vicious circle; Canadians have avoided solar because of high prices, and constant assurances that costs would and will eventually come down – so why pony up now for a system predicted to be soon obsolete?

It’s a reasonable concern. As such, Canada’s residential solar industry has concentrated on niches. First and foremost, water.

17 per cent of Canadian residential energy is consumed in the act of heating water. Nearly 10 per cent of Canadian homes have outdoor swimming pools. Heating an average-sized pool – even in the heat of summer – is actually more energy-intensive than heating a home in winter.

The solution? Solar panels, of course. It already heats about a tenth of the nation’s pools, and a modest $600 system makes a significant difference in energy consumption and bills. The reason is that solar heating is vastly more efficient than photovoltaic electricity.

It’s an exciting time for solar energy. The future’s so bright, it’s gotta wear shades.

Solar paint?

July 28, 2009

solarpaintSoon, the only tool needed to combat climate change could be a paintbrush. 

No more need for costly solar panels. The Corus Group, a Dutch steel company, has developed a way to paint solar cells right onto steel at the time of manufacture. 

Photovoltaic cells are the things in solar panels which generate a current or voltage when exposed to visible light. In other words, they’re what make a solar panel convert the sun into energy. Photovoltaic paint is a whole new type of ‘sun screen.’

The company says its paint is made into a liquid paste containing a layer of dye and a layer of electrolytes. Four coats of paint would need to be applied in total— an undercoat, a layer of dye-sensitized solar cells, a layer of electrolyte or titanium dioxide as white paint pigment and finally a protective film.

The solar technology is much like a plant’s photosynthesis and this boundary-pushing invention could have production starting by 2012. 

It means that one day all building surfaces that come into contact with the sun have the potential to become a photovoltaic surface. What is really exciting is the potential for deployment on a mass scale. Made possible because the paint would cost less than a solar cell, providing clean solar electricity at a low cost.

There would also be the added advantage for cloudier climates since the painted steel would be more efficient at capturing low radiation light than conventional solar cells.

Someday all your buildings could be three sheets to the sun.

Molten salt

July 20, 2009

saltYou know the expression, “ask ten people the same question, and get ten answers?” Here’s an exception: Ask a thousand people involved with solar energy this question, and you’ll get the same answer every single time.

Namely: “what’s the single biggest drawback to solar power?” That answer? Storage.

It’s definitely been solar’s Achilles heel, if you will. Solar-generated electricity is cheap, renewable, works on small and large scales, and the infrastructure is relatively cheap. But what do you do when it’s cloudy?

It goes without saying that electricity has to be available on demand. Previously, solar cells charged batteries (for the most part). That’s a decent solution, but batteries are expensive, bulky, and often inefficient.

A U.S. firm may just have invented the perfect solution, and it’s so high-tech you have to read the following sentence a few times to comprehend the complexity. Salt. Yes, you read that right. The world’s most common condiment may just be the future of electricity.

Okay, it’s more complicated than that – but not a whole lot more. Hamilton Sundstrand, a US aerospace company, couldn’t help but notice that when you heat salt to over 1,000 degrees, it melts and retains most of its heat energy.

The molten salt (actually a mixture of sodium and potassium nitrate) is stored in a tank until dispatched into a steam generator. The steam drives a turbine, which generates electricity. The salt retains 99 per cent of its heat per 24 hours, which is far better than most materials.

Sometimes progress is funny: a company devoted to outer space looks at a clean energy source from the skies, and improves it with…salt from the earth.

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