Sharp Corp, a leading Japanese manufacturer of solar cells has given a stark indication of European demand for solar production by investing £29.5 million in its British plant. Growing demand across Europe and in particular in the UK, following the introduction of tariff subsidies has seen the need for Sharp Corp to increase the output of solar cell modules in its Swindon based plant.

The increased investment gives encouraging signs not only for UK manufacturing in the face of the financial crisis but also renewable energy as a means of rejuvenating the struggling economy and generating jobs.

The feed-in tariff system, which came into effect in April this year was devised as a way of attracting investment in renewable energy and has proved successful in countries such as Germany and Spain where tariff payments have offset the initial costs of installing solar plant and offered attractive yields to investors. Sharp Corp have certainly seen an added interest in solar power, reflected by the investment in the manufacturing of essential solar components.

“This time last year 99 per cent of the modules that we manufactured at Wrexham were exported to Europe and that has already dropped to 90 per cent. The feed-in tariff has given confidence to manufacturers like ourselves to invest,” spoke Andrew Lee, General Manager of Sharp Solar.

Indeed, the investment in the UK plant will see four additional production lines taking the capacity of the factory up to 500 mW by 2011. In terms of job creation, the plant which currently employs 750 people is unsure about how many new jobs will be created but green shoots nevertheless for supporters of a low carbon economy.

Monitoring

How do I know if my PV system is working properly? This is a very good question and something that many customers of solar energy systems wonder. The answer is to spend some time and perhaps some money in monitoring the performance of your system over an extended period of time.

Perhaps the first point to mention is that a good installer should do this for you. They should care deeply whether or not their installations perform as well as they will have predicted. Before choosing your installer try to determine what they offer in terms of after sales support and care.

If you like to take matters into your own hands there are a number of ways to monitor your system. If you are not inclined to pay extra for monitoring hardware, the simplest solution is to use information from the displays of the generation meter or the inverter (or both). Both these instruments will be present in all PV systems installed in the UK by a microgeneration certification scheme installer and will be able to tell you the number units of electricity generated since the system was put in. Get into the habit of checking this number at the end of each day, along with a record of what the weather was like – clear sky, partial cloud, heavily overcast etc…

Your installer will have provided you with an estimate of the annual energy production in kWh – in southern England this should be in the region of 850 kWh per kWp). This means that over the course of the year you should expect an average of two and a half kWh of energy each day for every kWp you have installed. This is heavily dependent on the weather of course. On a clear day you could expect 8 kWh, and on a very dark day as little as 0.2 kWh. After several days of checking you should be able to have an idea of whether your system is significantly under-performing.

Over time, your measurements will become more reliable. Each month of the year has an expected solar energy output. Ask your installer for a chart showing the average monthly variation of solar energy for your location. After one month you can compare the energy you got with what you would expect. Be warned however, monthly solar energy output can vary widely, some months can be particularly good or bad for solar compared to normal, so comparing with the average is not necessarily accurate. Still, you should be able to tell if you are getting 30% less energy than you should be.

Getting a more accurate picture of your system’s performance is challenging. For instance, if your system is underperforming by 10%, how do you prove this?

A good method is to compare it to a nearby reference system which is known to perform well, and compare daily production to that. This can be challenging to find however, especially in the UK where there are still very few PV installations.

Another technique is to try to determine if there is something wrong with your system. Your inverter should also tell you the DC voltage and current coming from your solar panels. Under a clear sky, you can check if these values are in line with what they should be from the datasheet. Whether the voltage or current is lower than expected can provide information on what might be wrong.

If your system is underperforming, it could well be because of shading. If shadows are passing across the solar panels during the course of the day that weren’t accounted for in the system design, then this can really contribute to underperformance. Try to get in a position where you can see the solar panels at different times of the day. Any shadows on the module during the middle of the day (when they should be producing the most energy) can be serious. Many systems will be shadowed in the morning or evening, but this is generally less severe. Make sure to also check for dirt or muck on the panels, even small markings can cause big performance losses for solar systems.

It is also worth looking out for long term degradation. Whilst rare, it has been known for systems to get significantly worse over time.

If you would like buy a monitoring solution yourself then the simplest product is a power meter. Examples are the ‘OWL’ meter or the ‘Wattson’ made by DIY Kyoto. These are both simple meters that can easily be installed by clipping a sensor onto the AC output cable of your inverter. What’s useful is that the data can be transmitted wirelessly and viewed in real time and even stored to show you how energy production varies over the course of the day.

Depending on your installer, many will offer to monitor your system for you. This can be advantageous since they will have access to data from a large number of systems on which to benchmark performance. Make sure to ask them exactly how they plan to do this however.

On the upside, most systems should perform fine and are unlikely to go wrong but when you’re investing such a large amount of money in a PV system, its nice to know how to check its working.

President Obama has approved $1.85bn in loan guarantees for two large scale solar projects as part of the economic stimulus package. Combined these projects are thought to be creating 5000 jobs. Abengoa Solar is to receive $1.45bn in loan Guarantees to help support the development of a new solar farm in Arizona which is expected to power 70,000 homes.

 A further $400 Million in Loan Guarantees will be provided to Abound Solar Manufacturing to develop two new solar manufacturing plants. This is expected to create up to 1500 permanent jobs. It is an interesting move away from the Bush era’s pro oil approach. With the BP crisis in the gulf still in full swing Obama will face far less opposition in pushing these loans through. There will also be much stronger public support for renewable energy generally and drop in support for further off shore drilling programmes.

Obama is looking towards renewable energy as not only an investment in the environment but as a new industry to help rebuild America’s fragile economy. By investing in Solar power production Obama is opening a new income steam to the U.S and is also going to be competing directly with China who currently have huge solar panel production capacity.

 As more countries realise the importance of investing in solar energy and solar panel development we are likely to see increases in efficiency and a decrease in technology costs.

In the UK’s fledgling PV industry there are some unexpected issues emerging.
One of those is related to the grid or ‘mains’ voltage. This should be, as
in the rest of Europe, fixed at 230V. However it can vary, and in reality
the legal limit is 230V plus or minus 10 percent, generally being higher
voltage close to the nearest transformer, and getting lower voltage as you
move away.

This is important for PV systems because the inverter must convert direct
current into mains compatible AC with an acceptable voltage level. Inverters
are also designed to shut down if there is a problem with the grid for
safety reasons.

In Germany, the voltage level is very precise (perhaps as you might expect)
and since Germany is the world’s largest solar market by far, most inverters
in Europe have their settings with Germany in mind. This means that when the
grid strays slightly away from 230V, the inverter temporarily shuts down. In
the UK, the grid is much more likely to deviate from 230V, meaning that with
German settings, an inverter could well spend more time off than on.

Luckily the problem is generally easily fixed by changing the inverter to
new settings which make it tolerant to a wider voltage range. The key point
to remember is that with the inverter shortage, products are being sold
which are completely unchanged from their German settings. This means you
need to be extra vigilent when buying an inverter to ensure compatibility.

A related topic, that I will soon cover, is to do with how lots of solar
energy connected to the grid can actually affect the grid voltage and
frequency – but that’s another issue.

If an inverter is used in the UK without any change in settings then chances
are, with our fluctuating grid, you will have peaks or dips in the voltage
that shut off the inverter from time to time. The solution is simply to
change the settings via the firmware to allow the inverter to carry on
working in a wider range of voltages.