Concentrating Solar Power (CSP)

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Solar Power In Ontario Could Produce Almost As Much Power As All U.S. Nuclear Reactors, Studies Find

Saturday, April 17th, 2010

Solar power in southeastern Ontario has the potential to produce almost the same amount of power as all the nuclear reactors in the United States, according to two studies conducted by the Queen’s University Applied Sustainability Research Group located in Kingston, Canada.

One study, accepted for publication in the journal Computers, Environment and Urban Systems, discovered that if choice roof tops in southeastern Ontario were covered with solar panels, they could produce five gigawatts, or about five per cent of all of Ontario’s energy. The study took into account roof orientation and shading.

“To put this in perspective, all the coal plants in all of Ontario produce just over six gigawatts. The sun doesn’t always shine, so if you couple solar power with other renewable energy sources such as wind, hydro and biomass, southeastern Ontario could easily cover its own energy needs,” Professor Pearce says.

A second study, published in May issue of the journal Solar Energy, looked at land in southeastern Ontario that could be used for solar farms. The study considered land with little economic value — barren, rocky, non-farmable areas near electrical grids — and concluded it has the potential to produce 90 gigawatts.

“Nuclear power for all of the United States is about 100 gigawatts. We can produce 90 on barren land with just solar in this tiny region, so we are not talking about small potatoes,” Professor Pearce says.

Where Will Solar Power Plants Be Built—Deserts or Rooftops?

Tuesday, February 23rd, 2010

Both distributed and utility-scale solar energy projects are vital to accommodate the world’s growing energy needs as they are both suited to harness the extraordinary power of the sun. The underlying technology used by utility and distributed solar is different and understandably, each has its own proponents and detractors. For the most part, utility-scale solar projects use solar collectors to generate enough heat to power a steam turbine that in turn generates electrons. Distributed solar energy derives primarily from the use of photovoltaic panels that capture photons and convert them into electrons. Distributed PV efficiency is improving all the time. Currently, there is a conversion efficiency of approximately 17% for crystalline silicon panels and 10% for thin film panels — a dramatic improvement from only a few years ago.

In California alone, there are plans for 35 utility-scale projects that would generate approximately 12,000 Megawatts (MW) of energy annually — an amount of energy comparable to the combined power of ten nuclear power plants. The Mojave Solar Project and the Genesis Solar Energy Project, both located in southern California, are two of the largest projects under consideration and are each aiming to generate 250M watts of energy. These projects are expensive, however, in terms of both dollars and natural resources required. The federal government has promised to help reduce the financial cost by allocating a portion of the stimulus plan for this purpose. Companies that have their plants ready to be opened by the end of this year will receive a portion of the $67 billion of federal money that has been set aside for renewable energy projects (including loan guarantees and grant programs).

Despite these incentives, it is risky to undertake a large-scale enterprise like utility-scale solar power in an uncertain economic climate, as financial institutions are reluctant to be involved in billion-dollar projects. Another issue is the fact that such solar ‘farms’ require huge tracts of land. Another challenging issue for utility-scale solar projects is the use of water. Combined, the Genesis and Mojave projects would use 1.24 billion gallons of water per year due to the wet cooling systems involved.

An alternative to utility-scale projects is the use of distributed solar energy. There are various types of renewable power technologies in use, but sub-utility scale power photovoltaics (PV’s) account for 98% of the distributed solar energy market. Unlike utility-scale projects, distributed energy is solar power on a small scale and entails the installation of solar panels on the roofs of buildings.

Distributed solar power does not involve the legal red tape, the large tracts of land, or the vast quantities of water that utility-scale projects require, and has the ability to generate enough energy for homes, schools and hospitals. Installation is easily addressed and solar panels can last for up to 30 years if well maintained. The price of solar panels has dropped dramatically to approximately $2.40 per watt (price depending on scale of order) for silicon panels and is likely to drop even further in 2011. Furthermore, unlike utility-scale projects, distributed solar projects such as the Southern California Edison’s Plan spread capacity evenly, distributing benefits and drawbacks. If a utility-scale project “crashes,” it affects a huge area. With distributed energy, only individual units are affected in the case of a power outage.

In many locations and in certain circumstances, distributed solar projects are less expensive than utility-scale solar projects because of the avoidance of both new transmission lines and line losses — the latter of which typically accounts for approximately 7% of the power shipped over transmission systems. The costs associated with utility-scale solar projects are often not included in the side-by-side economic comparison made between the two forms of solar power development. An additional benefit of distributed solar is its ability, when developed in clusters (i.e., local micro-grids), to alleviate the need to upgrade distribution substations and add local peaking plant capacity.

As mentioned, distributed solar plans have their detractors. Solar certainly is not the cheapest source of electricity and is only effective in areas with a high percentage of sunshine. More than 50 million Americans live in Community Associations where we might expect to see efficient adoption of distributed solar plans. But these locations commonly have policies limiting the use solar equipment due to height restrictions or other specifications regarding roofing materials.

Solar-driven Stirling engines get to work

Saturday, January 23rd, 2010

Business and government officials on Friday cut the ribbon on a solar array in Arizona that uses giant parabolic dishes to generate electricity from the sun.

Solar plant developer Tessera Solar installed 60 solar collectors, called the SunCatcher from Stirling Energy Systems, in Peoria, Ariz. Each dish is rated at 25 kilowatts and the entire facility will have a capacity of 1.5-megawatts of generation.

Utilities installing large-scale solar power generation are typically using arrays of flat photovoltaic panels or concentrating solar power systems, where mirrors or reflective troughs create heat to make electricity.

The Stirling Energy Systems technology also captures heat by using a mirrored parabolic dish that moves to track the sun. But instead of heating a liquid to make steam for a turbine, the heat is directed at a hydrogen gas-filled piston, which drives a Stirling engine to make electricity.

The company claims its technology delivers electricity more efficiently and uses less water than other technologies. Inifinia is another company that has built a solar-powered Stirling engine using a parabolic dish, although it is smaller.

Commercial-scale solar developers pocket funding

Saturday, December 19th, 2009

Two solar project developers this week raised funds to install commercial and utility scale projects from a somewhat unlikely source: venture capital firms.

Although they are addressing different customers, both companies are in the business of renewable energy project development, where they build, own, and then maintain solar installations.That model is typically used for non-residential solar because third-party financing makes investment far more attractive to prospective customers such as businesses and utilities.

Tioga Energy provides power purchase agreements in which the customer doesn’t have to pay the upfront cost of the solar panels. Instead, it purchases the electricity generated by the panels from Tioga, which finances the installation and manages ongoing operation.

Financing renewable energy projects is typically done by banks or companies specialized in project financing, but that source of money has dried up in the economic downturn. Venture capitalists, meanwhile, have typically stayed clear of project finance because they seek bigger financial returns by investing in technology or business model innovations.

But General Catalyst is starting to look at project development companies as part of its mix of investments, said investor Bilal Zuberi in his blog. “Strong execution, plus control over a scarce resource, allows a developer to not just create value from projects on the ground but also from future pipeline of projects,” he said.

Posted in Commercial Solar PV, Concentrating Solar Power (CSP) | No Comments »

Sahara Sun ‘to help power Europe’

Sunday, December 13th, 2009

A sustainable energy initiative that will start with a huge solar project in the Sahara desert has been announced by a consortium of 12 European businesses.

The Desertec Industrial Initiative aims to supply Europe with 15% of its energy needs by 2050.

Companies who signed up to the $400bn (£240bn) venture include Deutsche Bank, Siemens and the energy provider E.On.

The consortium, which will be based in Munich, hopes to start supplying Europe with electricity by 2015.

Desertec Industrial Initiative aims to produce solar-generated electricity with a vast network of power plants and transmission grids across North Africa and the Middle East.

“The time has come to turn this vision into reality,” said the company’s chief executive, Paul van Son.

Solar Millennium Switches to Dry Cooling

Tuesday, November 17th, 2009

Solar Millennium said Monday it plans to use dry cooling for its solar thermal power project in Nevada.

The Berkeley-based company announced the switch, which could add to its project’s costs but win it some goodwill from lawmakers and environmentalists, after its plan to use as much as 1.3 billion gallons of water per year for its project met strong opposition from residents of Amargosa Valley.

Using air cooling could cut the water use by 90 percent from the original proposal, the company said. Dry cooling techniques are generally more expensive and lead to lower efficiency for the plant. But water is a precious commodity in the deserts of western states, where many solar thermal power plants are under development.

Solar Millennium is proposing to build one or possibly two solar power plants with 242-megawatt of generation capacity each. Each power plant would cost about $1.5 billion to build, the company said.