If I had a pound for every time I’d heard that comment I’d be a rich man. That’s not to say it’s a dumb question though, it’s a perfectly reasonable question – it’s clearly sunnier in the south of Spain than in Blackpool. The question is by how much and does it matter?

At any given moment its not easy to predict how it’s going to be, but over the course of the year, the overall sunniness level can be accurately measured and predicted. This value is called the irradiation and can be defined as the amount of energy hitting a 1 square metre area pointed towards the sun over a whole year. In the south of England, according to the European Commission’s Joint Research Center, we get 1100 – 1200 kWh of irradiation per year (a kilowatt hour, kWh, is a typical unit of energy). In Devon and Cornwall you get between 1200-1300 kWh per year and in the North of England and Scotland its 1000-1000 kWh. In contrast, Barcelona gets 1700-1800 kWh of irradiation per year and in the very south of Spain and Italy it can get up to over 2000 kWh per year. So comparing London to Barcelona that’s 50% more irradiation for the Catalonians, which is significant but doesn’t mean we should give up hope for solar energy in the UK.

There are some other factors to consider here; irradiation doesn’t correspond exactly to the amount of solar energy you get out of a PV system. The best solar panels on the market today are only around 18% efficient under good conditions. At high temperatures for example, solar panels become less efficient. If the temperature of the solar panels increases by 20oC, they will only produce around 90% of the energy they would at room temperature. This means that on a clear but cold day in London, solar panels could produce more energy than a hot and sunny day in Spain.

Another factor is the difference between clear days and cloudy days. In the UK we get a lot of cloudy weather which blocks the sun and leads to ‘diffuse’ sunlight (meaning from all directions) rather than ‘direct’ sunlight. The four sunniest months of the year in the UK (May-August) deliver 5 times as much solar energy as the four winter months of the year (Nov-Feb). Solar panels can still turn diffuse light into electricity though, and there is evidence to suggest that some types of solar panels are better at collecting it that others. This means we may be able to improve the difference between London and Barcelona by using different technologies.

Despite these factors though, solar panels in Spain will of course still produce more energy than solar panels in the UK, which makes energy from solar cheaper in Spain than over here. But in some ways what happens in Spain is irrelevant, the question that really matters is whether solar energy makes sense or not in the UK.

I would say it does. With the feed-in-tariff, installing solar panels in the UK instantly becomes a highly profitable exercise yielding significantly better returns than most savings accounts (discussed in a previous article). Much of Germany, where over half the world’s solar panels were installed in 2009, is on the same latitude as the UK (northern Germany is in-line with Newcastle). So if it works over there, it should work over here.
The second point is that prices of solar energy systems are falling and electricity prices are due to rise, leading to so called ‘grid parity’ – the point at which solar electricity costs the same as regular electricity and can flourish without government support.

Because Spain is sunnier, grid parity is expected to happen there sooner than here (some claim it may have already happened in certain cases). Several predictions indicate however (in particular those from the EPIA – European Photovoltaic Industry Association), that we can expect grid parity in the UK as early as 2013 or 2014. In just a few years solar energy will be competing on real terms with retail electricity prices, hardly a waste of time in my opinion.

So the next time someone greets you with incredulity at the prospect of using solar panels in the UK, you at least have some numbers to back yourself up…

You heard it here first. Sources recently disclosed to me that we can expect an announcement from the UK government concerning the feed-in-tariff in mid-to-late January.

You may well be aware that while the government has committed to launching a feed-in-tariff program to support renewable energy, it has not confirmed the value of the proposed tariff yet. Numbers have been suggested, but we do not know the exact price per kWh of energy that will be paid to producers and this is causing significant problems for the UK PV industry when advising customers.

The long-awaited announcement will be closely scrutinized to see whether the UK government is serious about meeting its renewable energy targets. Given that the UK is the last major European economy to introduce a feed-in-tariff program (by a considerable margin) the industry will be hoping that the price set will be strong enough to allow the UK to gain some of the lost ground.

Solarfeedintariff.co.uk, the group of solar energy specialists dedicated to green issues and leading exponents of solar energy has announced that it will be offering a solar installation quotation service via its website.

To request a quote CLICK HERE

The service will help both businesses and homeowners navigate the often complex world of green investments by offering advice as to the best solar packages available.

With a broad range of experience in the solar photovoltaic sector, solarfeedintariff.co.uk is aware that many investors in solar panels are put off by the all too confusing array of products and technology available in the market.

Solarfeedintariff.co.uk will seek to eradicate any confusion and clarify doubts by offering the right product to customers depending on their needs.

Ian Spencer, Managing Director of Solarfeedintariff.co.uk stated that,

“Ever since the website was launched, we have had enquiries requesting quotes for Solar Installation, especially with the Feed In Tariff (FIT) due to be launched in April. WE are now delighted we can offer this services, using one of the leading Solar Installation firms in the UK”

With great opportunities available to reduce energy costs and of course, help slow the process of global warming solarfeedintariff.co.uk will be rolling out a service which will help both households and businesses save money, also taking advantage of the UK government’s Clean Energy Cash Back System, designed to incentivise investments in green energy through cash rewards.

With a vast array of products on the market, often from far away manufacturing bases in the far east, it can often be difficult for first time solar panel purchasers to discern the good companies from the… not so good and to calculate whether attractive looking offers are actually as great value as they first appear.

With a sharp eye on the market and with a passion for promoting solar installation in the UK, Solarfeedintariff.co.uk is keen to make the whole process of solar panel purchase and installation as smooth as possible, offering peace of mind to customers and promoting customer friendly, ethical companies.

Ian Spencer added,

“We expect the demand for Solar Installation quotes to rapidly rise the nearer we get to April and the dramatically increase on the Feed In Tariff is more widely recognised and known about. Therefore, we are pleased to be able to offer this service now for all of our site visitors”

To request a quote CLICK HERE

Solar panels fall into two main technological categories. The incubant, established tyoe are called crystalline silicon solar panels and the exciting but unproven type are known as ‘thin-film’ solar panels. To understand the advantages and disadvantage of each technology I’ll briefly explain how each type of solar panel is made. Crystalline silicon solar panels are made from 50 or so ‘solar cells’ connected together and encased in glass. Each solar cell is in fact a thin slice of large crystal of pure silicon (called an ingot). These large crystals are grown from a seed crystal surrounded by molten silicon at very high temperatures. The silicon used must first be extracted from silicon dioxide (also known as sand) and then purified to a very high level. Once the crystal is formed it can be sliced into wafers. The wafers are then specially treated to make a junction between a positive and negative type semiconductor, and then other layers such as the conductive contacts are added to make a working solar cell. This process has many steps and consumes a lot of energy. However, many companies have spent a lot of time refining the process to make it as efficient as possible so almost all parts of the process are now automated.

Thin film solar panels are made using a radically different process. The underlying physics is similar in that they still use a junction between a positive and negative doped semiconductor, however thin film solar panels have the potential to be made in much fewer steps than crystalline silicon. The idea is to take glass (or sometimes foil or plastic) and coat it directly with a series of layers, including the active semiconductor layers to produce a working solar cell. The glass is then encapsulated with a protective plastic and a second sheet of glass as protection. This process saves having to make lots of small cells and connect them together. The other advantage is that the layers are very thin, hence thin film solar cells. The active layers of the cell are only a few nanometers (billionths of a meter) compared to 0.2mm for each silicon wafer.

The important point of all this is that the manufacturing cost of thin film solar cells has the potential to be significantly lower than crystalline silicon. Unfortunately, there are some catches. Firstly, they are not as efficient as crystalline silicon. Crystalline silicon reaches 16 – 18% efficiency in modern solar panels, whereas the most efficient thin film solar panels on the market today  are under 11%. The next drawback is reliability. Thin film solar panels have had less time to prove themselves and have been known to suffer from degradation meaning that their performance gets significantly worse over time.

Despite these drawbacks, several companies have managed to become very successful in manufacturing thin film solar cells. The most notable is called First Solar who are now one of the top two largest solar panels manufacturers in the world and have a significant advantage over rivals due to their low manufacturing costs. First solar make thin film solar cells made from cadmium telluride, one of a number of semiconductor materials that can be used for thin films. First Solar’s panels are less efficient but are very popular for large scale solar installations because of their low cost.

Before the financial crisis, when silicon was in short supply and very expensive, all thin film solar panels were a good idea. First Solar could not produce enough and billions were invested in a large number of thin film solar companies aiming to follow in their footsteps. Now that the silicon shortage is over and the price of crystalline silicon solar panels has fallen, the environment for thin film solar cells is more challenging. First Solar will remain a strong player as they have managed to get to high volume and have a reliable production process. Many of the 200+ start-ups hoping to replicate their success will struggle however. For thin film solar cells there are a wide range of different manufacturing processes and materials that can be used, and there is still a lot of research being done to improve our understanding of the underlying physics. This means that there is a lot of opportunity to invent a ‘unique’ technology and start a company but only the best thin film solar companies will make it however. They have to show not only that their technology is efficient and reliable, but also demonstrate that large scale production is feasible and low-cost. Many ideas that look good on paper or in the lab turn out to be impractical when it comes to volume manufacturing.

At present, it seems like crystalline silicon will retain a strong market share for the foreseeable future (it current represents 80-90% of the market) but I believe that eventually certain thin film technologies will begin to displace crystalline silicon. There is a lot of potential for efficiency improvement in thin film, as well as lower manufacturing cost. Some technologies, particularly that usce solution processing are really very exciting.

What does this mean for the UK solar industry? Very little actually. I would expect over 90% of the UK market will be crystalline silicon for a long time. The reason is that the UK market will be dominated by smaller rooftop applications (partly due to the structure of the feed.in tariff as discussed last week). In such space-constrained applications you want to use the most efficient technology to maximize the energy generated from the available area. For now, this means always choosing crystalline silicon as it’s efficiency is significantly above any thin film solar panel out there.

Keep an eye out for breakthroughs in solar technology as some are surely bound to occur, but beating high quality crystalline silicon solar panels made in China for cost, efficiency and reliability is not easy.