Posts tagged ‘solar 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

August 13, 2015

See-through solar cells

Solar cells are mostly thought of as covering a roof or a large field of reflective solar panels in the middle of the desert. But recently researchers at Michigan State University developed a solar cell that is transparent, and so could bring amazing possibilities. Being transparent means that these cells could be used in many more places than traditional solar cells – including windows and other glass surfaces like phone screens – without interruption to doing their job of collecting the sun’s energy. transparent-luminescent-solar-concentrator-module-640x424

As the basic principle of solar cells is to absorb the sunlight in order to turn it into electricity hence shouldn’t let it through (which means they shouldn’t be transparent), this novel solar PV cell in fact is a so-called transparent luminescent solar concentrator (TLSC). It includes special organic salts than can transform certain types of non-visible wavelengths of light (UV and infrared) into a different type of non-visible light (also infrared) and this is then beamed to the traditional solar PV cells located on the rim of the solar cell.

The current efficiency is about one per cent (with expectations to increase it to five per cent) but it can be scaled up when applied at building windows, or it could be used to extend the battery life of mobile devices.

Prior similar solutions were mostly coloured, but the new technology allows them to be fully transparent, opening up a range of new surface options.

Michigan State University scientists are not the only ones trying to utilise large glass surfaces.

SolarWindow Technologies took another approach by having developed a see-through liquid coating that can be applied to glass that can harness solar energy. The materials used are organic, offer great performance and it’s claimed to be working well even in shaded areas and in artificial light!

Ubiquitous Energy is another company focusing on the development of transparent solar cells. Their solution technology is a film that lets visible light through but filters and absorbs ultraviolet and near-infrared light, which it turns into electricity. They claim that the efficiency can be more than ten per cent.

With so many different approaches to the same idea, see-through solar cells might be here soon.

Image credit: Michigan State University

July 25, 2013

Solar Trains

Solar-powered cars are known to be widely tested but it may not be common knowledge that there are already a number of trains all around the world that get their energy from the sun.

In Belgium, 16,000 photovoltaic panels are installed on top of a 2.1 mile long rail tunnel, which power about 4000 trains. Electricity consumption of these trains fell by 30 per cent thanks to this development.

Solar tunnel in Belgium

Solar tunnel in Belgium

Also, in India there are two solar trains in operation: The Himalayan Queen and the Shivalik Express are both diesel trains featuring solar panels on their roofs. The Himalayan Queen is fully powered by the solar panels and it can run for two days without sun. Inside lighting on both trains is LED lights and offer solar charging sockets for travellers. By installing solar panels The Shivalik Express has also become significantly lighter and so it consumes less diesel than previously.

Italy’s PVTRAIN project uses the electricity generated by solar panels to power air conditioning, safety systems as well as lights.

Some short-distance trains are also completely solar-energy-powered. In Norwalk, USA at the Stepping Stones Museum for Children a Solar Train offers a ten-minute train ride thanks to 4000 solar cells on its roof. A similar solar-powered train is running In Hungary’s Nature Reserve Kiralyret Forest, where the vehicle was built by the locals.

Besides trains, even railway stations are becoming part of the sustainability revolution. London’s King’s Cross station has just been renovated and is now home to a large number of sustainable and energy-efficient solutions, including an on-site Energy Centre, which should provide all heat energy the development needs, in addition to green and brown roofs, sustainable urban drainage solutions and lower carbon emissions.

All-in-all, solar energy-driven trains are now chugging along on all parts of the world: India, North America, Italy or Belgium. And as solar panels enable lower emissions, decreased costs and even ‘free’ electricity onboard, the spread of such solar trains may even accelerate.

January 22, 2013

Energy co-operatives

Co-operatives are traditionally an efficient and successful way for communities that aim to live or work with certain benefits through co-operation. Co-operatives are usually created by people working, living together or by those consuming products or services as a group.

Utility co-operatives have been around in the US since the New Deal but recently there are more and more such co-operatives set up all around the world, which focus on green and alternative energy usage.

These co-ops provide an opportunity for local people to invest into various projects, for example setting up new solar panels or a wind turbine. Then, the co-operative provides interest for these investors from feed-in-tariffs or by selling electricity.

In Germany, the number of energy co-operatives has tripled to more than 600 in two years, with over 80,000 active members. The largest of these is EWS, where 99.2 per cent of the electricity comes from renewable sources and 0.8 per cent is from the co-generation of heat and power (CHP).

But Germany is not alone. In the UK, there are also an increasing number of such community initiatives.

Brixton Energy already has two existing solar projects in the Loughborough Estate with hundreds of square metres of solar panels, while Community Energy Warwick raised enough money for solar panels to be placed on the roofs of the Stratford upon Avon and Warwick hospitals. Meanwhile, the Brighton Energy Co-op recently set up “the largest solar system in Sussex”, with installations in Shoreham-by-sea, Portslade and Brighton.

But the list goes on: Leominster Community Solar, Ovesco, Bath & West Community Energy, Westmill Wind Farm, Baywind Energy, Hockerton Housing Project, Boyndie Wind Farm, and many others – with a total of 75 utility co-ops listed with Co-operatives UK.

Renewable energy co-operatives thus could mean the future for renewables with local communities joining forces to gain access to cheap (or free) energy sources by working together.

Written for the Energy Saving Warehouse 

January 15, 2013

Heated pavements – wasted heat or saving resources?

When talking about heated pavements, the first thought that would come to one’s mind would be – what a waste of energy and heat! However many existing schemes in Northern cities could show that these heated ‘roads’ could be beneficial and may even save resources.

A recent pilot project in the Netherlands for example is investigating the possibility to collect and store summer heat underground and release it in the winter months to keep the bicycle lanes ice-free. The benefits could mean less salt used and probably more cyclists on the roads.

In Northern countries, like Norway or Iceland, heated pavements are already well-established – in the latter one mainly fuelled by geothermal energy.

The company ICAX has developed its unique  ‘Solar Road Systems’, which collect the heat in the summer for road heating and de-icing in the winter. Their technology utilises the fact that black tarmac used on the road surfaces can heat up significantly in the sunshine, and by storing this heat – it can be used in colder months – for free. Their first successful trial in the UK took place under an access road to the M1 motorway at Toddington, Bedfordshire. Furthermore, the firm also claims to provide a solution for de-icing runways and parking stands at airports, potentially lowering disruption at busy terminals in snowy conditions.

Another company, Solar Roadways from Idaho, USA [4] has tested specially designed glass panels, with multiple features. These contain LED lights – which could display for instance road signs – , while the heating elements can help melt snow and ice, improving winter driving conditions.
This system is currently quite expensive due to the materials used, but there are also some cheaper alternative methods being investigated. One of these is using photovoltaic panels and cells on the roads, with embedded pipes for storing energy until colder times.

For a small town in Michigan, USA, this idea is nothing new. Here, waste heat from the local power station has been used in the underground pipes to melt the ice on the pavements since the installation of this system in 1988.

Also, there are already many commercially available personal under-driveway and under-pavement melting systems and mats, but these are costly and may not be very environmentally-friendly.

Hence, if cold winters continue to be harsh, heated pavements could be seriously considered as one of the long-term solutions for easing winter problems.
Written for the Energy Saving Warehouse

 

January 3, 2013

Biophotovoltaics

Have you ever thought about using photosynthesis to power your desktop lamp or your laptop? Biophotovoltaics researchers are just working on that now.

Scientists at the University of Cambridge  have created the so-called ‘Moss Table’, Moss Tablea table with an array of pots of moss, which can already generate enough electricity to power a digital clock. For the operation, the moss only needs access to light and water in order to perform photosynthesis, which can then lead to power generation. Although current power output is rather low, it has the potential to be much more significant in the future.

The operation is rather simple. The moss (or other plants, algae) photosynthesise, which allows some organic compounds to enter the soil. When these compounds are de-composed by the bacteria in the soil, by-products are created, including electrons. These are then collected by conductive fibres integrated into the table and then used for powering devices.

According to another biophotovoltaic research, photosynthetising cells can be isolated in grass cuttings or other plant material, and these cells could then be added to various surfaces to create solar cells. The efficiency of these at the moment is also rather low but the technology is being improved day by day.

Biophotovoltaics is another promising research area, which could allow solar energy to become a direct household energy resource for anyone.

 

June 10, 2012

What is Thermoelectricity?

Thermoelectricity means to gain electricity directly from the heat difference of two parts of a material – and it can also work in reverse. This means that by introducing an electric current, the material could be either heated or cooled down. The technology has already been used for power generation in spaceships, and the reverse is applied for heating car seats, food carriers or computer chips.

One of the main challenges of thermoelectricity is to find the right material. The perfect material should conduct electricity well but not heat, in order to work appropriately. This is rather hard to find and so nano-scientists have been working on solving this issue. A Norwegian team for example recently introduced nanoscale-barriers into common semiconductors, which helped them in lowering heat conductivity, while keeping the electronic conductivity – just what’s needed for utilising thermoelectricity.

Thermoelectric materials may be ideal for ‘replacing’ current photovoltaic (PV) cells, according to some scientists. This would be thanks to the fact that they can utilise a much broader spectrum of solar energy, and thus they could provide better performance. A Professor from the University of Arizona recently suggested that thermoelectric paint on top of roofs with solar panels could be applied to achieve better performance and eventually for lowering costs.

Thermoelectricity could also be a great solution for using up waste heat. Waste heat is the energy created by machines that is not utilised for anything. According to estimates this is currently about half of all energy in the world, and is generated by industrial processes, combustion engines and power generation, amongst others.

Thus if the right materials are identified or created thanks to nanotechnology, thermoelectricity could be one of the key future technologies, which could help in various fields.

Written for the Energy Saving Warehouse

May 24, 2012

Plastic Solar Cells

While the cost of solar panels in general is decreasing, the main material solar cells are made of may become scarce in the future. This is silicon, and it’s in high demand as it’s used in many industries – for instance at the manufacturing of computer components or for waterproofing treatments. Scientists have however announced the development of the first plastic solar cell. Is this maybe a solution for the future?

The Center for Organic Photonics and Electronics at Georgia Tech has discovered a new method for printing electronics. The process itself is not new as it has been used at organic solar cells or OLEDs but until now the manufacturing stage was more problematic due to potential chemical reactions by the metals that have been used. The new technique could solve the issue by applying a thin layer of polymer on the surface of the conductors, which will chemical reactions and does not need an extra layer of protection. Thus the manufacturing process can become more stable, and as electronics can be printed onto plastic, it shall become cheaper and easier. And also the polymer used is cheap, easily available and environmentally friendly.

Earlier, researchers at the University of California developed a polymer solar cell, which efficiency exceeded even those made of silicon. It features two layers of plastic that react to different bands of light: visible and infrared, which enables the increase of efficiency.

Konarka Power Plastic usage

Konarka already offers its solar product, Power Plastic, which is thin, flexible and comes in various colours – including transparent design. They have been specially applied on bags or on various surfaces, like carport tops or tents.

Another company, Solarmer Energy has also developed an organic plastic solar panel, with several great features that offer new fields of application, including portable electronics, smart fabrics and buildings.

Polymer solar cells are not only thin and light, but their low cost could mean a significant price drop for this market, and researchers are already working on the manufacturing challenges.

Written for the Energy Saving Warehouse

Image: Konarka

March 14, 2012

Would You Live in a Passivhaus?

Passivhaus is an energy efficiency standard, developed in 1988, which sets out various criteria for homes and commercial buildings for maximising energy savings – thanks to its orientation, materials used and insulation, amongst other features.

This standard sets maximum values for energy consumption of space heating, cooling, primary energy usage, as well as the highest temperature inside and the level of air tightness – not allowing virtually any air to leak from the house. These requirements can however vary in different countries due to different circumstances, for instance the age of existing buildings.

Passive houses have to be designed and built precisely to the specifications – for maximum gain. The most important features include the specific positioning of walls in order to capture the most sunlight, or the super air tightness. Despite some myths windows on these houses can be opened but due to excellent indoor air quality, the air ventilation system and other factors it’s usually not needed.

Various materials are used for the construction and even the colour of the outside wall is suggested to improve efficiency through either absorption or reflection. Insulation has to be of highest standard and very thick, both at the walls and the roof.

Meanwhile, heating is hardly required as a Passivhaus also utilises the heat energy generated inside the building, for instance by various appliances. Thanks to the careful design interior temperature does not go below 15C  and due to the air tightness there are no cold spots or mould growth inside these buildings.

Lighting solutions are also energy-efficient, thanks to the use of solar-powered lights outside or LED lamps inside – amongst others.

Another great advantage is that such houses can be built in any climate, and there are now over 30,000 such homes all over the world.

Also, the main criticism of being very expensive is addressed by the continuously decreasing construction costs, while savings could be enormous. In the case of a UK office building, the company Interserve in Leicester managed to save GBP 26,000 at their annual energy costs after moving into a Passivhaus.

Thus, passive houses may mean homes of the future for us or our companies, offering significant energy savings, which is also important for our wallets.

For more info, check out: Energy World, March 2012, “Passivhaus in the UK – an alternative to zero carbon”

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

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