May 17, 2020

Beyond Solar Panels: 6 Types of Solar Power Plants

fresnel reflector
4 min
Solar panels aren’t the only way to tap the power of the sun.  These different types of solar power plants will show you how!



Photovoltaic Panels
These are what come to mind when most people think of “solar power”—rows of flat solar panels mounted on top of a building or strewn along the side of a highway. Photovoltaic solar panels work thanks to a principal known as the photoelectric effect, in which certain materials exhibit a property of absorbing light photons and releasing electrons. By capturing these electrons an electrical current can be created.

Photovoltaic technology has come a long way since its discovery in 1839 by French physicist, Alexander Edmond Becquerel. It was over 100 years later, in 1941, that the first practical silicon monocrystalline PV solar cell was developed, and since then advancements in materials and production have led to thinner and more durable designs with widespread commercial use.

Now, giant photovoltaic farms—capable of producing hundreds of megawatts of electricity—are being developed by top companies like First Solar, SunPower, Sharp, Q-Cells, Suntech, and Yingli.

But photovoltaic solar panels aren’t the only type of solar power plant out there, and more exotic power plants are using the power of the sun in some very different ways.

Parabolic Troughs
Imagine rows of reflective troughs—like curved mirrors—reflecting the sun’s light and concentrating it on thin tubes of liquid (usually oil) that run the length of the troughs. The liquid is heated by the concentration of the sun’s rays to 400° C and carried via tube to a power station where it boils water to create steam and run power-generating turbines. The troughs are mounted on mechanized tracking units that follow the sun’s movement to increase efficiency.

This is the concept behind the parabolic trough solar power plant, and in just the last few years several of these power plants have popped up all over the world, capable of producing hundreds of megawatts of electricity. The added advantage of storing the sun’s rays as heat allows these power plants to continue to operate into the night and during intermittent cloud cover by regulating the heat transfer fluid. Companies leading the way with solar troughs include Spain’s Abengoa and Acciona.



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Solar Dish
Solar dishes—like giant mirrored satellite dishes—operate in a similar fashion to parabolic troughs, but focus light onto a central point mounted above the dish. Some systems use the concentrated solar heat to create steam; however, a more efficient system has been created by Stirling Energy Systems Inc. and has already been employed in the Maricopa solar plant in the sunny deserts of Arizona in the United States.

The Stirling “SunCatcher” is a solar dish that tracks the sun and focuses light on a central power converter unit. The unit is filled with hydrogen gas, and when heated by the concentrated sunrays, the gas pressurizes to turn cylinders in a power-generating engine. It operates much like a combustion engine minus the combustion, making it relatively quiet, and it is hailed as one of the most efficient and cost-effective solar systems on the market.

Fresnel Reflector
This design functions in much the same way as parabolic troughs, but instead of using expensive curved mirrors, Fresnel reflector solar power plants use several rows of flat mirrors all angled to focus on the absorption tube. This can be a cost-effective alternative to parabolic troughs, since flat mirrors are much cheaper to produce than curved ones. Companies streamlining production of Fresnal reflector systems include Elianto, AREVA and Novatec Biosol.

Solar Power Tower
Now imagine something like a giant solar dish—with thousands of mirrors (called ‘heliostats’) positioned on the ground to reflect sunlight upward to the top of a giant central tower. The top of this tower houses a bulbous metal chamber of molten salt (or water in some models) that absorbs and stores the concentrated heat from the reflected sunrays in order to boil water and use steam to run power-generating turbines. Companies like SolarReserve, eSolar, Abengoa, BrightSource Energy, and SENER have been pioneering the solar power tower market, with several plants operating in the Spain and one in the U.S.

Solar Chimney
This design heats the air in a giant enclosed canopy that surrounds a gargantuan central tower. The tower acts as an escape chimney for the hot air created in the canopy. Since heat rises, the hot air will push its way out of the canopy and up through the tube-like central tower. Turbines are placed within the tower to harness the energy of the updraft and generate electricity. While these towers and their canopies need to be built on a massive scale—think larger than most New York City skyscrapers—it is important that they serve a dual purpose, and since the canopy that heats the air acts as a gigantic greenhouse, hundreds of acres of cash crops can be planted within, increasing the power plant’s overall utility. Australian company EnviroMission Limited is on track to develop the first large-scale solar tower project in the deserts of Arizona in the United States.

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Apr 21, 2021

UK Government pledges to cut carbon emissions by 78% by 2035

3 min
UK Government to enshrine new emission targets in law by the end of June as Prime Minister Boris Johnson targets new technologies and green innovation
The UK government has agreed to stick to Climate Change Committee recommendations and cut carbon emissions by 78% by 2035 compared to 1990 levels, it announced today.
The sixth Carbon Budget limits the volume of greenhouse gases emitted over a 5-year period from 2033 to 2037, taking the UK more than three-quarters of the way to reaching net zero by 2050.
The budget will ensure Britain remains on track to end its contribution to climate change while remaining consistent with the Paris Agreement temperature goal to limit global warming to well below 2°C and pursue efforts towards 1.5°C.
For the first time, the budget will incorporate the UK’s share of international aviation and shipping emissions – an important part of the government’s decarbonisation efforts that will allow for these emissions to be accounted for consistently.
This comes ahead of Prime Minister Boris Johnson addressing the opening session of the US Leaders’ Summit on Climate, hosted by President Biden on Earth Day (April 22). The Prime Minister will urge countries to raise ambition on tackling climate change and join the UK in setting stretching targets for reducing emissions by 2030 to align with net zero.
The government is already working towards its commitment to reduce emissions in 2030 by at least 68% compared to 1990 levels through the UK’s latest Nationally Determined Contribution - the highest reduction target made by a major economy to date. Today’s world-leading announcement builds on this goal to achieve a 78% reduction by 2035.
The new target will become enshrined in law by the end of June, with legislation setting out the UK government’s commitments laid in Parliament tomorrow.
Prime Minister Boris Johnson said the UK will be home to "pioneering businesses, new technologies and green innovation as we make progress to net zero emissions".
Through its presidency of the crucial UN climate summit, COP26, which will take place in Glasgow later this year, the UK is urging countries and companies around the world to join the UK in delivering net zero globally by the middle of the century and set ambitious targets for cutting emissions by 2030.
The government has already laid the groundwork to end the UK’s contribution to climate change by 2050, starting with ambitious strategies that support polluting industries to decarbonise while growing the economy and creating new, long-term green jobs.
This includes the publication of the Industrial Decarbonisation Strategy, an ambitious blueprint for the world’s first low carbon industrial sector, slashing emissions by two-thirds in just 15 years, as well as over £1 billion government funding to cut emissions from industry, schools and hospitals.
Further, the UK is the first G7 country to agree a landmark North Sea Transition Deal to support the oil and gas industry’s transition to clean, green energy while supporting 40,000 jobs.
Through the deal, the sector has committed to cut emissions by 50% by 2030, while the government, sector and trade unions will work together over the next decade and beyond to deliver the skills, innovation and new infrastructure required to decarbonise North Sea production.

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