Posts tagged ‘renewable energy’

October 30, 2016

Cutting edge ways to utilise buildings for electricity

Tesla and SolarCity-owner Elon Musk has just revealed their latest product, called the ‘Solar Roof’, which is essentially tiles with integrated, high-efficiency solar cells behind tempered glass.

The new solar tiles are stylish as one can choose the most matching look for any building from the four different styles available (textured glass, slate glass, Tuscan glass, smooth glass tile). By using glass, the durability of tiles is increased and might even outlast the building’s life as claimed. There is a slight loss of efficiency (they work at 98 per cent), but the company is working on improving this rate.

Tesla claims the new roof could be more affordable than conventional ones when calculating utility costs as well, and when bundled with Tesla’s Powerwall ‘personal battery solutions’, households of the future shall be able to generate most of the power they would use.

Meanwhile researchers are also working on how to utilise windows to generate electricity. 30146569762_36de14f9b8_bScientists at the Los Alamos National Laboratory, New Mexico, have published a paper in Nature Energy claiming that a thin film layer of ‘quantum dots’ added to existing windows could enable low-cost window-based solar photovoltaic (PV) systems, which could reach higher efficiency (up to six per cent) than current systems. Quantum dots are nanometre-sized semiconductors, which enable scientists to set which type of light is absorbed. The layer is easy to apply, and the silica-protection protects against oxidation, for enabling durability.

Photos: Tesla Solar and Los Alamos National Laboratory, New Mexico

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May 2, 2013

Island Power

Islands and coastlines are in a controversial position regarding climate change. 800px-AgrihanNASA

On one side, as we expect today ocean levels will rise significantly and coastal cities and regions, as well as islands, are threatened the most.

On the other hand, climate change also makes us more aware of the downsides of traditional fossil fuels and renewable energy are becoming more and more significant. Besides wind and solar, there is a further medium that can offer significant amount of energy: water. And islands and coastal areas are the best sites to take advantage of wave and tidal power, being surrounded by seas and oceans.

According to the World Energy Council the potential amount of energy that can be sourced from just waves is between 8-80,000 TWh globally, and up to 2000 TWh per year seems to be economically feasible today but technological innovations in the future could increase this figure. 

The waters around the UK have been identified as one of the best locations for both tidal and wave energy, with a potential of up to 60 GW of electricity – which is approximately 75 per cent of the total electricity needs in the UK currently. 

There are already a number of large-scale devices being tested and installed in the surrounding seas, with the two key areas being the Pentland Firth and Orkney Waters Marine Energy Park in Scotland and the South West Marine Energy Park between Bristol and Cornwall, which have recently signed a Memorandum of Understanding about future co-operation.

Collaboration however can also extend across borders. The Marine Energy in Far Peripheral and Island Communities (MERiFIC) is a great example of international co-operation between the British and the French, involving members from Cornwall, Finistere, le Parc Naturel Marin d’Iroise and the Isles of Scilly. [3]

The MERiFIC initiative aims to investigate opportunities and threats, the economical and technical feasibility of marine energy utilisation in the area, besides a number of joint tests and research projects. Members, including the University of Exeter and University of Plymouth, have been working on developing a framework for other international partnerships that can be used by similar communities on other parts of the world.

International alliances like MERiFIC hence may mean a successful way of looking into the future in the renewable energy sector.

 

March 4, 2012

Enhanced Geothermal Systems

Heat from the earth has been tapped for a long time. However while conventional geothermal systems utilise the energy from underground only at locations with ideal geological features – where hot water and thus steam already exists -, now also less favourable places can enjoy the benefits of geothermal energy – thanks to Enhanced or Engineered Geothermal Systems (EGS).

These systems use the potential of the “hot dry rocks” under our feet for generating heat and electricity. In the case of the conventional geothermal energy, known as hydrothermal, hot water is in situ, while the new technology artificially fractures hot dry rocks, and then circulates cold water, which eventually turns into steam and so drives turbines on the surface. Later the water is re-injected and the loop is started again.

According to a study by the MIT Enhanced Geothermal Systems have the potential to provide 100 GWe generating capacity just for the US in the next fifty years. This technology is scalable and can provide a continuous base load, but further investigations, including field tests, are needed to determine the real benefits.

Potential challenges include that it may cause minor tremors, and it requires a rather large initial investment, which may hinder companies and countries who are willing to finance such projects.

Australia is already leading the way in testing this technology, while there are further trials in Germany, as well as France and the US. In the UK the Eden Project is one of the latest examples.

According to the forecasts of the European Commission EGS systems can offer cost-effective electricity virtually anywhere, with an estimated potential of 1 GW and a maximum potential of 6 GW for the EU countries by 2020 – about one per cent of gross electricity consumption. For heating purposes the potential is even higher. The EU has supported about ten projects since 2002, including the key pilot project in Soultz, France.

Enhanced or Engineered Geothermal Systems thus offer great potential both for heat and electricity generation and hopefully with more investment it can be developed into a promising new energy source.

Written for the Energy Saving Warehouse 

February 29, 2012

A New Way of Carbon Capture? Let’s Plant Artificial Trees

Trees lock away and store carbon-dioxide for hundreds of years. Scientists now want to mimic this feature by creating artificial trees for our parks, which could even act as street lights and harness wind power.

The key scientist behind the idea is Dr. Klaus Lackner from the Earth Institute at the Columbia University. His “synthetic trees”resemble real trees with trunks and branches, which are in fact arrays with sorbent chemicals for capturing the carbon-dioxide.

Synthethic Trees

Leaves can be more dense than on normal trees, increasing efficiency. Also, the collected carbon dioxide could be utilised and not only stored, for instance in agricultural processes.

Another concept is the so-called uTree, a photovoltaic tree that would soak up the sun during the day, then fed into the electricity grid or even stored inside – for instance for lighting spaces.

Some artificial tree ideas go further and try to merge the various capabilities. Some may harvest rainwater and generate electricity via solar panels at the same time. Some others act like solar street lights, or create a whole park with saving rainwater and even using wind energy.

Challenges for artificial trees are the high initial investment, long-term maintenance costs and some worries about the actual efficiency of small artificial leaves compared to solar panels, but if these can be overcome, walking in the park could have a new meaning in the future. [6]

Written for the Energy Saving Warehouse

Image: BBC Online

January 17, 2012

Solar Energy in the Himalayas?

The majority of solar panels are installed in warm countries with plenty of sunshine but according to a recent studypeople living in higher regions, where it’s cold and sunny, can soon benefit from solar energy, too.The study investigated the feasibility and efficiency of PV cells at high altitudes like the Himalayas, the Andes or Antarctica, and concluded that these could be used even more efficiently than in ‘traditional regions’ due to the specific conditions.  

Here, up in the mountains, the atmosphere is thinner and so less energy is lost, enabling more available light for the solar cells. Also, the cold environment helps keeping cells of certain materials (e.g. silicon) cool, allowing improved efficiency.

Another advantage is the free renewable energy that could improve the everyday lives of local, poor communities.

Solar systems in Tibet

The first such solar systems have already been set up in Tibet.

Recently, Suntech Power announced its plans to develop a 10 MW solar power plant in Tibet, after the company already installed a solar system in a base camp on Mt Everest and donated several solar systems to schools as well as communities in the region.

Earlier this year, another company, OSolar also launched a state-of-the-art tracking solar installation in Lhasa with great potential for energy efficiency.

Challenges

There are some opinions that these cells are not developed for the humidity and pressure they would have to face on those hillslopes but the study suggested that such cells would still have good efficiency in such conditions.

It should also be noted that some of these cold regions have harsh weather phenomena like hail or strong winds, which can physically harm solar cells [6].  In existing small-scale solar systems in the Swiss and Austrian Alps, components are sturdy, so they can withstand such severe conditions.

Despite these challenges high-altitude solar power may be one of the areas with the most potential for harnessing the Sun’s power.

Written for the Energy Saving Warehouse
Image: Corbis – Source: Discovery News
January 1, 2012

Hygroelectricity – Power From the Air

No, it’s not a typo. Hygroelectrcitiy is a new type of renewable energy that scientists are researching and experimenting with.

But what is it? Hygroelectricity is basically power collected from the charged droplets in humid air

The theory was introduced last year by Fernando Galembeck Ph.D from the University of Campinas in Brazil at the 240th National Meeting of the American Chemical Society (ACS).  According to him air particles are not neutral as it is currently thought but can become charged. He proved this in his laboratory with silica and aluminium phosphate particles, which became negative and positive – respectively. These particles are generally present in the air surrounding us.

According to his idea, this energy should be later available for specially designed collectors (similar to solar cells), which can transfer the energy to be used in homes or, for instance, in cars.

But Dr Galembeck is not the first one trying to harvest energy from the air. Nikola Tesla already investigated atmospheric electricity, with special focus on lightning.

Benefits

Besides obvious advantages, hygroelectricity can be an alternative energy resource in humid climates, primarily the tropics, where access to electricity may be an issue today.

Also, the research into charged particles in the air can help scientists to  understand lightning, and even prevent injuries and damage by through using hygroelectronic devices on buildings to retrieve the charge out of the air.

Challenges

One of the biggest questions regarding hygroelectricity is how much energy can actually be harvested, which according to some experts is rather small. Also, collection designs have not yet been developed.

Also, the electric charge of water particles is still a very controversial topic, and not all professionals believe that the lab results can work the same way in real life.

Despite these challenges however, scientists agree that it could be a very promising research area, which could bring great results in the future.

 

Written for the Energy Saving Warehouse

Image by vegadsl

 

November 18, 2011

A New Momentum for Geothermal Energy in the UK?

When we talk about renewable energy in the UK we tend to think about on- and offshore wind energy, solar power or the recently emerging new tidal and wave developments. And while geothermal energy is often forgotten about it seems that they may receive more attention in the future thanks to renewed interest from developers.

When is geothermal energy efficient?

Geothermal energy is essentially using the heat of the Earth, ‘generated’ by the radioactive decay underneath us. The most ideal places for harnessing this heat depends on the geothermal gradient of the area, the temperature difference between the surface and the core of the Earth. This is on average 25-30C degrees per kilometer increasing with depth, but can be significantly higher in areas near tectonic plate boundaries or in places where the crust is thinner than usual.

Geothermal energy can be used in two ways: the hot water and the hot dry rock found below are used for heating (directly or indirectly) as well as for electricity generation.

In the UK

Despite the lack of popularity of geothermal energy projects there are already some successful developments in the UK.

One of the earliest developments exists in Southampton, where a Combined Heat and Power (CHP) station operates, providing district heating, not only used in houses but also in shopping malls and hotels in the city – since 1986.

Also, last year the Department of Energy and Climate Change (DECC) announced the ‘Deep Geothermal Challenge Fund’, which awarded significant funding to three projects in Newcastle and Southampton.

In the Gardens of Eden

The latest large-scale project is probably the planned geothermal power plant of 5MW at the Eden Project in Cornwall. This part of the UK is one of the most suitable places for geothermal energy development thanks to its geology, featuring granite bedrock.

The drilling to the hot dry rocks underneath is expected to start next year after all permissions have been granted, and should reach a depth of 4-5 kilometres. Besides the Eden development it is anticipated to also provide power for 3-4000 homes in the area.

The project seems to be rather promising, which could mean that the whole geothermal energy segment might gain momentum in the UK in the near future.

Reasons could include that geothermal energy is available 24 hours a day; it’s clean, sustainable, but not greatly supported by the government – yet.

 

Written for the Energy Saving Warehouse

November 16, 2011

OTEC, Energy From the Sea

OTEC is an emerging technology that harvests energy from the ocean but does not involve waves or tides. OTEC stands for Ocean Thermal Energy Conversion.

This technology is actually not that new, as first attempts for developing an OTEC solution took place at the end of the 19th century and it has been more seriously researched since the 1970s, however the increasing focus on fossil fuels paused these developments.

Today, Japan is one of the most interested countries in the technology having started tests in 1970 with a 100 kW plant by the Tokyo Electric Power Company, while nowadays the Saga University runs a dedicated laboratory. India has also recently joined the group of key researchers, while the US has its main experimental site on the technology in Hawaii, at the National Energy Laboratory.

OTEC - Lockheed Martin.com

How does it work?

The system utilizes the temperature difference of the deep cold water and the warm surface waters, producing electricity through heat engine systems.

There are three types: open, closed and hybrid cycle technology.

In the open-cycle system the seawater is pumped into a low-pressure chamber so it boils, vaporises and powers the turbine, thus generates electricity. Later the cold seawater helps in condensation, and the seawater will become pure water, which can then be used for various purposes or re-cycled.

The closed-cycle system differs in that a low-boiling-point fluid is used, usually ammonia or freon, which is heated through a heat exchanger by the warm seawater. Another heat exchanger helps at the condensation phase.

Hybrid systems combine the two technologies.

Where can it be used?

As with all heat engines the greater the temperature difference the better the results. Thus the OTEC technology could be used best in the tropical waters with about 20 degrees difference between warm surface (typically about 25C) and cold deep water (about 5-10C at one kilometre depth). This means it could be promising for islands, especially those facing regular challenges with constant electricity supply.

Systems can set up on land, on continental shelves or they can float to provide easy access to deep cold water.

Two new facilities are planned now in the Bahamas as agreed between Ocean Thermal Energy and Bahamas Electricity. These are expected to be the first commercially operating ones, not only providing electricity but also fresh water and would support sustainable food production.

The Maldives is planning to also investigate the technology in the rush to improve renewable energy usage in the country.

Also, the DCNS Group focuses on various marine energy resources and plans to build OTEC systems on the La Reunion Island, in the Indian Ocean. They have also been working on a feasibility study for Tahiti, and a 10 MW-factory is planned for Martinique.

Pros and Cons

Advantages of OTEC include its continuous operation, as it is not prone to changing weather conditions like wind, waves or tides, and it can support desalination processes hence offering clean water. The system can also help in areas where cooling is needed, for instance for agriculture or air-conditioning.

One of the main disadvantages is the difficulty of finding the right location, efficiency and so feasibility.

As issues with fossil fuels grow it seems that research on OTEC technology may be gaining momentum again.

Written for the Energy Saving Warehouse

Image: Lockheed Martin

 

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