BP Says Goodbye, Google and Buffet Say Hello

While BP steps away from the solar business, Google and Warren Buffet continue to invest.

Full Story [Energy Efficiency News]

The Passive Side of Solar

Not that solar PV and concentrating solar power are aggressive. They’re active, and passive solar is more easy-going, don’t worry about electronics or mechanical devices; just let the sun do all the work.

Like its more active cousins, passive solar begins with design. Situate a building; let’s say a house, to take advantage of natural sunlight and natural air currents. That way, the house benefits from warmth and ventilation. Put lots of large windows on the south-facing wall (if you live in the Northern Hemisphere, north-facing wall if you live in the Southern Hemisphere), and maybe a deciduous tree or two outside the windows. Build the roof with a large overhang. Provide some sort of thermal mass, like a tiled concrete slab floor or a brick wall. And that is basically it. Sit back. Relax.

In the summer, when you really don’t need the heat, the sun is directly overhead and the overhangs and trees prevent direct sunlight from coming through the windows. In the winter, when you do need the heat, the sun is lower in the sky and the trees have shed their leaves, and sunlight comes directly through the windows, warming not only the room, but also the thermal mass. Once the sun sets, the thermal mass releases its absorbed heat to the room, reducing the need for furnace heat.

Let’s say you’ve done all this but when you stand back and look at your house, you think “Gee, the south-sloping roof looks bare, but I don’t want solar PV panels and all the wiring and batteries they entail. What can I do?”  Well, you can consider a solar collector. Solar collectors consist of piping that is surrounded by dark, heat-absorbing material overlain by a transparent film or glass to avoid heat loss and backed by insulating material, again to avoid heat loss. The heat-absorbing material transfers its heat to a fluid circulating through the pipes that run into the house. The fluid, in turn, transfers its heat to a heat sink such as a water tank or thermal wall to be used for water or space heating.

With passive solar, the only work you’ll need to do is open the curtains. And close them at night; they make a good thermal barrier.

PVs, Troughs and Towers – Electricity from the Sun

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.

Energy BOT Squad’s Newest Member

This week just got a little brighter with the introduction of SolarBOT, an energy dynamo who can soak up the rays and heat up the town. Add in his ability to generate electricity and you’ve got a BOT who can take it easy and stay powerful at the same time.

One of the most familiar uses of solar energy comes with solar photovoltaic (PV) panels. Disturbed around the country on rooftops, ground-mounted installations and anywhere that sunlight can reach them, these panels can provide power to locations and devices that wouldn’t otherwise be able to reach the grid. Certain locations provide more sunlight for these panels, making areas including southern Ontario, Quebec and the prairies the best places in Canada for SolarBOT to kick back and absorb.

But SolarBOT does more than just keep power flowing, he also keeps Canadians warm. Active solar thermal systems use mirrors or metal plates to focus the sun’s energy, transferring the heat to air or water. And once that air or water has been heated, it can be distributed throughout a house, keeping it toasty warm.

And not all solar heating is active either. Passive solar heating simply involves constructing a home so that the sunlight naturally finds its way into the home and its heat is trapped by insulation. After all, what’s a nice sunbeam if you can’t relax?

In Canada, the solar industry is represented by the Canadian Solar Industries Association (CanSIA), which provides public information on solar power and industry information for companies in the business of harnessing the sun’s energy. Governments have also stepped into the business of promoting solar power, with Ontario’s Feed-In Tariff (FIT) program and its guaranteed prices for solar power being the most prominent example.

Around the world, solar power has been able to provide emission-free energy in a variety of locations, including large facilities like the 40-megawatt solar farm in Sarnia, Ontario. Globally, facilities like the US’s Solar Energy Generating Systems (SEGS) are providing megawatts of installed capacity, from North America to Europe and beyond. So even if SolarBOT occasionally likes to kick back, he’s always a powerful BOT.

You Decide

The Department of Energy and Climate Change in the UK is challenging you to solve the problem of reducing the country’s CO2 emissions by 20 per cent of 1990 levels by the year 2050.

The data behind the 2050 simulation is based on actual UK data. You read along and learn about how the country uses energy and then decide how you see its future. The program quantifies your ideas and prompts further questions about the impact of your choices.

When you are done you get a snap shot of what your world looks like – again nicely quantified and easy to understand – including geography references, scale and scope of development that would be required, nod to efficiencies realized and a literal count of things like wind turbines and nuclear power plants that would be required. You can return to your musing and try again or submit the results.

But what we really like about this sim is that it’s the foundation for the Pathway Debate. Eight climate and energy experts have set out how they think the UK could meet the target using the 2050 tool. Brilliant. This is one of the best online tools we’ve seen recently to help consumers understand the relationship between supply and demand. It’s about the energy mix and how all of the sources work together to power the future. So hop to it and take a spin or should we say a sim.

Really, everyone these days is an energy armchair critic, picking winners and losers and thinking they have a better idea. Now it’s your turn. You decide. And you just might learn something in the process.

Totally Renewable – and Renewed – by 2030?

In our recent post on the World Future Energy Summit, we discussed the need for policy change in order to achieve current climate change targets. Two scientists in the United States have taken that one step further. Mark Z. Jacobson, professor of civil and environmental engineering, Stanford University and Mark A. Delucchi, research scientist, Institute of Transportation Studies, University of California, Davis; believe that all that is needed to achieve a totally carbon free, totally renewable, wind, water and solar (WWS) based energy system by 2030 is political will.

Well, maybe a bit more than that. We’ll also need:

• 490,000 tidal turbines, each with an installed capacity of one megawatt
• 5,350 geothermal plants, each with an installed capacity of 100 megawatts
• 270 additional hydroelectric plants, each with an installed capacity of 1,300 megawatts
• 3.8 million wind turbines, each with an installed capacity of five megawatts
• 720,000 wave powered turbines, each with an installed capacity of 0.75 megawatts
• 1.7 billion rooftop photovoltaic systems, each with an installed capacity of three kilowatts
• 49,000 solar focusing steam power plants, each with an installed capacity of 300 megawatts
• 40,000 photovoltaic power plants, each with an installed capacity of 300 megawatts

Basically, to achieve a totally renewable WWS energy system, we’ll have to totally renew the existing system. And that includes building a new, super-interconnected electricity transmission grid. It also involves scrapping all internal combustion engine vehicles and replacing them with electric or fuel cell vehicles.

And the cost estimate is only about $100 trillion.

The most fascinating aspect of this theory is that it might just be doable.

The U.S. Energy Information Administration predicts that by 2030, world energy demand will be 16.9 terawatts (TW), or enough to power 47 60-watt light bulbs for every person on earth. But Jacobson and Delucchi point out that in a carbon-free world there would be no internal combustion engines, and internal combustion engines are far less efficient than electricity, so the actual requirement drops to 11.5 TW.

And if you think 3.8 million wind turbines is a lot, consider that auto manufacturers make 73 million cars per year. Also consider that much of the world’s electricity generation and transmission infrastructure is aging and will have to be replaced in the not too distant future anyway. And without all the transportation-induced air pollution, medical and environmental costs would decrease significantly.

As far as reliability of the system is concerned, a thoroughly interconnected grid will be able to re-route surplus electricity to wherever it is needed. Jacobson and Delucchi point out, perhaps a little simplistically, that if it’s raining in one place, it’s sunny someplace else, or if there’s no wind, it’s probably sunny. In other words, electricity will be generated somehow, somewhere.

The authors have determined that the only technical barrier might be the availability of rare-earth metals needed for batteries, solar films and fuel cells. But if we recycle old batteries and buildings, we should have ample supply of steel, concrete and things like neodymium and indium.

Which means the real barrier is political will, which ultimately means getting everyone onside. Most of us agree there’s a problem, but maybe it’s a little far fetched to try and achieve all this by 2030. Maybe it’s more realistic to try for 2050. Implement a more gradual shift, replacing old infrastructure as needed with new wind, water and solar generation. Maybe people will be a little more comfortable with that and a little more willing to put one of the 1.7 billion photovoltaic systems on their own roof.

Read the paper in the journal Energy Policy, Part 1 (600KB PDF) and Part 2 (680KB PDF)

Via Green Tech, cnet News

Keep the Sun Shining

It’s been a while since Flow tackled the issue of geo-engineering — the theoretical science of not just reducing our emissions to address climate change, but actively trying to change the climate. Perhaps because the proposed technologies are nearly all as drastic as you’d expect from a science based on literally engineering the planet — installing CO2 “scrubbing” air filters, encouraging CO2-consuming algae blooms — geo-engineering doesn’t often get a lot of attention. But now, one geo-engineering solution is getting a nod from none other than the United Nations itself, in the form of a proposed ban on any technology designed to block the sun.

While it’s easy to notice the oddly super-villain-like tone of a ban on massive orbital sun-blocking technologies, it’s also important to remember that any effective geo-engineering solution would necessarily involve the whole world. Allowing one country to unilaterally control the world’s climate would be an issue of national security.

The body responsible for this discussion is the UN’s Convention on Biological Diversity, which has already issued another geo-engineering-related directive limiting the use of iron in the ocean as an algal fertilizer.

Solar energy is a phenomenal source of energy, with the Earth receiving a full 1.8×1014 kilowatt-hours of energy. According to the World Energy Council: “if only 0.1 per cent of this energy could be converted at an efficiency of only 10per cent it would be four times the world’s total generating capacity of about 3,000 [gigawatts].”

Rogue nations with massive mirrors and geo-engineering enthusiastic alike, beware:
We’re watching you.

Via Popular Science

Urchin power!

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

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

Bigger And Biggerer

When we talk about solar power, we’re not always thinking big. It’s exciting to discover, for example, that there’s actually a species of ocean-bound bacteria that can photosynthesize just like land-based plants, and we’re always hearing about solar-powered devices like solar backpacks that can fit just about anywhere. But sometimes, bigger really is better — at least when we’re talking about megawatts.

At 100 MW, the Shams 1 solar power plant will certainly be producing more power than even the most incredible solar backpack. The plant will be built by Total (a French oil firm) and Abengoa Solar (a Spanish solar firm), and its 768 collectors will eventually cover 2.5 square kilometres. The project is intended to be the first of three, to be followed by Shams 2 and 3, and will take about two years to complete.

Despite being one of the world’s largest producers of oil, the UAE is no stranger to large-scale, headline-grabbing renewable energy projects. The largest of those, Masdar City, will eventually be the home of the International Renewable Energy Agency (IRENA), showcasing a variety of renewable energy and energy efficiency-related features.

Like Masdar City, Shams 1’s size provides two main benefits: a critical mass of energy production and, perhaps more importantly, a very public environmental offset to the emirates’ main export. But is it big enough?

When it comes to solar power, it can always get bigger: every day, the Earth receives the equivalent of 174 petawatts of energy from the sun (though over a third is reflected immediately by the upper atmosphere). The UAE are going to need a much, much bigger solar backpack for that one…

Via Popular Science

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