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Monthly archives: June 2010

The sun shone upon the festival goers at Glastonbury last week with usual scenes of rain and mud put on hold as thousands flocked to that corner of Somerset. With sunburn and dehydration an obvious risk for the crowds, the UV rays would have proved a welcome sight for Michael Eavis who plans to build the biggest solar farm in the UK. Eavis, the founder of Glastonbury festival hopes to take advantage of the recently introduced feed-in tariff to earn money for the energy he generates on the site.

The plan will consist of 1500sqm of panels at a cost of £550,000 on Pilton Farm and will be situated on the cow shed dubbed ‘Mootel’. With an obvious substantial outlay involved in the construction of the 1100 panels, Eavis will utilize the feed-in tariff to generate an income based on the units of energy his solar farm produces.

The feed-in tariff works by offering a guaranteed, premium rate for the units of renewable energy produced by the solar panels be they fed-back into the national grid or simply consumed by the owner of the farm. Eavis’ system for example expects to generate around 200 kilowatts of electricity a year generating £45,000 in income from the tariff, enough to pay for the installation in six years. With a 25 year lifetime of the project, Eavis can hope to generate a healthy profit once the high cost of the installation is recovered.

Although Michael Eavis is investing £50,000 of his own money into the solar farm, the rest is being invested by Triodos Bank who specialize in green investments. Eavis, explaining why he chose to invest his money in solar power stated,

“I’ve been planning this for a long time but the Gulf of Mexico oil spill has brought home just how urgent it is that we move to renewable electricity. We have already bought all the recycled fat from chip shops that we can find to run the generators during the festival and we wanted to create a permanent source of renewable energy. It makes sense to use some of the massive amount of free energy that comes from the sun.”

Understanding how to design a PV system is not rocket science, but it is more complex than many people consider. Here’s a very quick overview of the important points.

Solar panels produce direct current (DC). This means you need an inverter to turn that electricity into mains frequency alternating current (AC).  Inverters come in a range of power ratings. The more solar panels you have, the more power the inverter has to deal with, so the size and cost increases. It’s very important to match the size of the inverter to the number of solar panels.

If the inverter is too small, you will lose out on some of the energy that your system produces. If it is too large, the inverter may not perform at its optimum efficiency, and you will have paid for more than is necessary. In the UK, the optimum situation is to have an inverter that is rated at 80% of the power rating of your PV system, since it is rare you will be producing at 100% power.

More critically than getting the power right, you need to ensure the voltage and current of your solar panel system remains within the input range of the chosen inverter. To re-cap, solar panels on your roof are generally connected together in series, in a ‘string’. This increases the system voltage, but does not increase the current. Once a certain number of solar panels have been connected in series, the voltage will become too high and the system needs to be arranged in two strings, each of the same number of panels, connected in parallel. This generally occurs after a string exceeds 8 – 11 solar panels. When strings are connected in parallel, the currents add-up, but the voltage remains constant.

By adding more and more strings in parallel, the current and voltage can be controlled to remain in the inverter limits. For large solar installations, inverters can used that that have a very high power capacity, or alternatively it is possible to use many small inverters connected in parallel.

It is important to remember certain constraints. Inverters come in several sizes, but there may be some numbers of solar panels for which no inverter is ideal. For instance, because it is necessary for all stings to be equal in size, you can only use an even number of solar panels when using multiple strings. In addition, all solar panels must receive the same amount of sunlight when connected to the same inverter. It is no good to have some solar panels facing different directions on different parts of the roof. New technologies, soon to become widely avaialable that will make this process much easier. Namely micro-inverters, which convert DC to AC at every solar panel, will mean that solar panels can face different directions, however these are not yet widely available.

If you have a sales visit from a solar company, make sure the salesman understands these points as he’s designing your system.

With the huge oil disaster in the Gulf of Mexico still fighting for column inches with the FIFA World Cup in most parts of the world, it still remains a highly emotive subject in the country where it is having the most devastating impact. The Gulf states of the US are reeling under the blow to their economy, environment and way of life with an understandable backlash now both in the media and in Washington towards the oil industry and in particular, BP.

With this public maelstrom directed at the hapless BP, a leading energy attorney, Greg Chaffee has stated that the disaster will inevitably lead to more investments in green energy. Chaffee who practices at Morris Manning & Martin and also acts as the chairman of the MMM Green Industry Practice stated that,

“This is more evidence that the Gulf spill disaster has become a wakeup call for a nation that remains firmly addicted to oil.”

With specific reference to BP, Chaffee added,

“Not only should the federal government hold BP accountable for its errors and misjudgments leading up to the disaster, the federal government is now positioned more than ever to be the catalyst for funding research and development on alternative fuels.”

The Obama administration has already given its commitment to leading the way in green technologies with other leading countries such as China giving backing to funding in renewable energy sources. Chaffee however believes that what is really needed is not government legislation but a root change in the culture of the public.

“If we do not mobilize our resources now to concentrate on our energy future, we will be missing a key opportunity to positively re-shape the economic and environmental future of our nation. Weaning ourselves from our addiction to oil does not begin at the White House. It begins at home.

Each decision we make daily – from the cars we drive, to the containers in which we store our food, to how high we set the thermostat has an impact on our demand for oil. It’s that demand which led us to drill a mile beneath the ocean floor in the Gulf of Mexico.”

As usual, it seemed that the UK was falling behind competitors from abroad from a reluctance to look to the future and fully back green energy through strong legislation. Solar markets in Spain, Germany and Italy to name but a few in Europe, attracted investment through incentive schemes in the form of feed-in tariffs. With the UK government finally introducing the Clean Energy Cash Back scheme in April 2010, it now appears that the financial mechanism is in place to help UK solar investment catch up with more mature markets overseas.

According to many within the industry, the UK now has everything in place to become a player in the global solar market.

“The UK market for solar PV is growing explosively. This is because the FITs [feed-in tariffs] bring a huge new raft of players – the energy users – into the market; broadening it way beyond the traditional energy industry. All renewable power sources are benefitting, but solar is doing best because it is so easy to apply,”

Commented Philip Wolfe, Director of Ownenergy and leading exponent of feed-in tariffs.

With the tariffs working as a means of incentivisation for investors who were once reluctant to invest in what was once an extremely expensive field, the tariffs offset costs and greatly improve the attractiveness of green energy investments. In all countries where tariffs have been introduced there has been a massive uptake in investment with individuals keen to take advantage of legislation-protected investments with healthy ROIs.

With regards to potential for the solar PV industry, Edwin Koot CEO of Solarplaza stated that,

“Having experienced the benefits that FITs have to offer, European countries are now looking to capitalise on the emerging UK market. We can already see signs of this happening for our upcoming UK PV Conference: where 67% of delegate registrations are from international companies, compared to just 33% from the UK.”

However, warning that in the current climate the UK solar PV industry is unlikely to achieve overnight success, Clive Collison of South Facing said,

“It will take time to develop the UK market. Currently there is a lack of knowledge so education of potential customers and businesses is needed. Right now, very few people understand the feed-in tariff system and the opportunities to their full extent.

It took Germany, Spain and Italy three years after the start of their feed-in tariff to reach a substantial market scale. No doubt a similar market development will occur in the UK. That is why conferences like the UK PV Conference are important, to educate the business community and customers and build the business infrastructure. There will be plenty of business for everybody.”