Rugby FoE > Local Campaigns > Renewable Energy > Solar Power

Solar Power:

The West Midlands produces very little of the energy it uses, yet each UK home typically uses 4,700 units (kWh) of electricity a year and each unit costs about 7p each so that adds up to an annual electricity bill of around £329 per house. Therefore, Rugby's 39,000 households demand a yearly supply of over 183 GWh (183 million kilowatt-hours) of electricity for which we in Rugby collectively pay about £13million annually. Unless we get serious about reducing our energy use then we'll also be using even more energy for every household and with energy prices set to rise dramatically our electricity bills will become shocking.

To add to that Rugby is growing fast, with the building of up to 23,000 new dwellings by 2026 (an increase of 59% in 15 years).
Where will all their energy come from?

More renewables are needed:

Solar power has great potential to make a significant difference:

There are some moves locally towards encouraging on-site generation at point of use in order to try to help cut down our dependence on mains electricity.

Flyer for solar panel talk

    In 2010 Rugby Friends of the Earth held a talk for people thinking of putting solar panels on their properties to hear about what was happening locally in your community to save you money on installing solar solar water heating and electricity generation by helping you group together to get a better price and share costs.

    See our local case study on renewable energy generation telling the story of a dozen photovoltaic solar panel system fitted to a roof in Rugby. You will be able to follow its progress here on our website.

Photo of Reg taken by JJ

Local solar power saves on electricity demand:

Photo of Reg taken by JJ

Power stations tend not to be near centres of population, so there is an average power flow across the grid of about 8-9 GW (i.e. 8,000 to 9,000 megawatts) from the north of the UK to the south and on average about 5% is lost in transmission to get the power to the area where it is needed.

Solar power is popular:

Climate change is the most serious long-term threat not just to us but to wildlife too, yet solar power is emission free and comes from a renewable inexhaustible source; When compared to other power generation, solar power is also quiet, safe, not un-attractive, and has minimal impact on the land, residents and any wildlife.

Not surprisingly home owners are in favour of solar energy:

  1. Installation of solar panels is quick and simple
  2. Solar panels tend to go on roofs so very little land is used by the panels themselves. The larger installations are visible but not intrusive. Usually all of the land at the site can generally continue to be used as before.
  3. Solar generation creates no waste and, as the panels require no fuel, have no pollution or risk of accidents in the supply chain.
  4. Solar power provides clean, efficient, safe, sustainable energy that contributes to renewable energy targets to fight climate change
  5. Solar panels have a long life with little or no need for maintenance.

More use of solar power is needed:

It is estimated that for every hour of cloudless sunshine on an average summers day 1 kWatt of energy will reach every square metre of surface, though the amount varies according to cloud cover and location. The amount of solar energy that reaches the surface is known as the Insolation levels, expressed in kWh/m2/day (the amount of kilowatt hours per square metre of surface per day). Australia can average as much as 5.89 kWh/m2/day whereas Finland can be as little as 2.41 kWh/m2/day. The UK is nearer the Finland level and can expect around 2.61 kWh/m2/day, from a minimum of around 0.5 in winter to a maximum of around 4.7 in summer. Nearly all of this is converted to heat, though some of it powers chemical reactions, such as photosynthesis in plants.

On a local scale:

Micro-generation is needed: An average sized solar panel consisting of 36 cells (which can produce up to 12 volts) will be around 1m2 in size, so using the average insolation levels for London, that panel can be expected to receive around 18 kWh per week of sunlight (or 0.93-0.95 MWh per year), though of course most of this will not be captured and the efficiency of conversion to useful energy output will depend on the siting and quality of your system installation.

Site Selection:

You need a sunny roof or wall, ideally south facing, preferably angled at about 30 to 35 degrees and with as little shading as possible. However, if you are thinking of installing solar then the best thing to do is visit a site that has already had solar installed and talk to the owners about their experiences.

Nearby examples:

We would therefore welcome homeowners or community organisations with solar installed getting in touch with us that might be prepared to invite people to your house (or other building) so that they can see the systems in action. Please use our Feedback Form or see our Contact us page.

We are also asking for photographs of installations in the Rugby area that we can display here on this page. In this way we hope to be able to cover a variety of types of installations in the Rugby area including both PV and thermal on houses, offices and public/community buildings, both large and small in south-facing and more shaded locations.

There has been no negative effect on house prices, quite the contrary ...

and so we would welcome homeowners getting in touch with us that might be prepared to share some information on your return on investment and energy savings. Again, please use our Feedback Form or see our Contact us page.

Community Schemes:

Near Rugby there are now also several plans for community solar energy schemes on public buildings;
Community Energy Warwickshire Ltd (CEW) is a new volunteer led social enterprise, set up by people living and working in Warwickshire who want to take positive action to reduce our dependence on fossil fuels. In its first of a continuing series of projects CEW has teamed up with the NHS to install solar PV panels on roofs at Warwick and Stratford hospitals. CEW will be launching a community share offer to support the enterprise.

The developers are putting on exhibitions and holding consultations with the community, so if you require any further details please do not hesitate to contact them. Their details are available on their respective websites.

On a national scale:

Solar power could in theory provide 70% of the power needed for such things as directly heating water, though for electricity that is generated but cannot be used locally at that time and thus has to be stored for use later or sold to the National Grid for use elsewhere a number of practical reasons make the figure smaller (around 20% but improving).

Looking at the bigger picture:.

Concentrated solar power (CSP) mirror arrays covering just 1% of the Earth's deserts could generate a fifth of all the Earth's current energy requirements. It is the single biggest energy reserve



Posted by RugbyFoE |  June 2010  | Reg

Introducing Reg ......

A blog by members of
Rugby Friends of the Earth

Photo of Reg taken by JJ

..... the Renewable energy generator - a system of a dozen photovoltaic solar panels which were fitted to the roof of our house in June 2010.

We are members of Rugby Friends of the Earth and have agreed to submit regular information to the Rugby Friends of the Earth website about Reg's performance and other matters related to generating power by solar panels. The aim is to show how solar power can and does generate a worthwhile amount of electricity. This can be used in the household or exported to the national grid, thereby supplying a potentially significant proportion of the nation's energy needs from renewable sources.


Posted by RugbyFoE |  July 2010  | Reg

The basic requirements of the house for photovoltaic panels to work effectively are described here, followed by a brief non-technical description of the main component parts of the system and indication of its size and anticipated output, i.e.;

  1. Where should the panels go?
  2. What does the system include?
  3. How many panels are needed?
Read on...


Basic requirements:

Where?

House orientation:

Diagram of panel orientation

  • When fitting solar panels it's a major benefit if the house has a south-facing roof. This will ensure maximum exposure to sunlight.
  • The angle of the roof is also important. Somewhere between 30 to 35 degrees is said to be ideal.

Photo of Willow Tree taken by JJ

Fortunately our house met with these requirements although a very large tree, located close to the property, is likely to cause problems with shading during the winter months.

What?

Reg's main components:

Solar Photovoltaic Panels
Photo of Reg's HIT-240-HDE4 panel taken by JJ The 12 panels installed were manufactured by Sanyo. The type chosen was the HIT-240-HDE4 model. These hybrid panels, as they are called, are said to deal with shading problems more efficiently than other panels. As shading is an issue with our property we chose these Sanyo panels.
  • The general output of these panels is higher than for other mass produced solar panels. Each panel can produce up to 240 watts.
  • The dimensions of each panel are 1,610 × 861× 35mm.
Thanks to JH Power Solutions (now JH Solar Solutions) of Banbury for permission to use the photo with their staff member on it, showing the size of the panels.
The panels are fitted to a frame which is secured through the tiled roof to the beams of the house. Photo of Reg's panels being fitted to roof taken by JJ

Inverter

Photo of Reg's inverter taken by JJ An inverter is an appliance that converts direct current (DC) electricity to alternating current (AC). Reg's inverter converts the DC electricity produced as a result of sunlight hitting the surface of the photovoltaic panels to AC which can be used in the home or exported to the National Grid.

Data logger
This is not an essential part of the system but, if fitted, a data logger can be used to collect detailed information on the performance of the system.

The information from our data logger will be used to provide updates for the Rugby Friends of the Earth website on a monthly basis.
Photo of Reg's datalogger downloading data taken by JJ

How?

System capacity

The 12 x 240 watt panels give the system a potential capacity of 2.88 kilowatt peak (kWp). The kWp is the peak power of a system as tested under optimum conditions. The tests are standardised for panels produced by all manufacturers to ensure that comparisons can be made. The potential peak power is unlikely to be the same as the power that will actually be produced by the panels. In practice, this will be approximately 15-20% lower.

Reg, because of these losses that occur within the system and less-than-optimum conditions, including the tree shading losses, is expected to produce about 2100 kWh per year, 73% of peak.

Find out more

Find out more about what you can do to install your own renewable power at Centre for Alternative Technology (CAT) or at Renewable Energy Association (REA).


Posted by RugbyFoE |  August 2010  | Reg

Check on the web

Ascertain the potential solar power production capability of locations in the UK using the PV potential estimation utility - A website set up by the European Commission to help with this.

For a very basic assessment of what your own property might be able to produce, go onto the site and put in your postcode. Where it says 'Installed peak PV power' tap in the size of system you might like to install (providing you have enough roof space). If you are unsure of a system size, type in 2.5 (by way of an example) and click on Calculate; the site will do the rest. There is an assumption you that you have a south facing roof and the angle of it will be between 30-35º. The choice of panels is limited so simply go with the default of crystalline silicon. This site is not perfect but it gives a reasonable estimate for your own location.

Also visit the Energy Saving Trust's Solar electricity webpages

Follow our adventure in renewable energy generation:

Photo of Reg installed taken by JJ


Reg became operational on 11th June 2010. The whole installation was fitted by a Microgeneration Certification Scheme (MCS) certificated installer (essential to qualify for feed-in tariff, also known as clean energy cashback).

We hope to provide updates giving a general idea of Reg's performance and more detailed figures for energy production to date. To see how we get on with Reg and follow our adventures watch this space for further updates.


Posted by RugbyFoE |  September 2010  | Reg

So how is Reg doing?

Reg's output of electricity is recorded by the solar kWh meter.

Photo of REG'S Solar kWh meter taken by JJ Performance to date:

In the first 2 ½ months Reg produced 858 kWh of electricity.

Posted by RugbyFoE |  October 2010  | Reg

Feed in Tariff

On 1st April 2010 the Government introduced the Feed-in Tariffs (FITs) to encourage new investment in low carbon green technologies such as Solar PV. Under the FITs, anyone who installs an eligible Solar PV system will receive a guaranteed fixed payment for all the electricity they generate, including what they use, for a period of 25 years. They will also receive an additional payment for any electricity they don't use that they export into the National Grid. For a standard household system of 4 kWp or less the tariff is shown below in Table 3.


Table 3: FITS tariff

Size of System Tariff received until 31 March 2011 Tariff received between 01 April 2011 and 31 March 2012 Tariff received after 31 March 2012
4kWp or less (retrofit) 41.3p per kilowatt hour 43.3p per kilowatt hour 43.3p per kilowatt hour

If no export meter is fitted the export figure is 'deemed' to be half of whatever is produced. A further 3p per kWh is paid for export units.


Posted by RugbyFoE |  June 2011  | Reg

Update on Reg Performance June 2011

It is now one year since Reg became operational.

Reg's performance for the 12 months (11th June 2010 to 11th June 2011) can be seen in Table 1:

Photo of Reg's Birthday cake taken by JJ

Table 1: Monthly KWh production

Date

Monthly kWh Total

     
Jun-10 409 276
Jul-10 315 As the date of commencement
of operations was part way
through June 2010,
the calculation of the monthly
total for June is the production
from 11:30 am
on 11th June 2010,
to the end of the month,

and up to 11:30 am on
June 11th 2011

(276 + 133 = 409).
Aug-10 255
Sep-10 183
Oct-10 125
Nov-10 66
Dec-10 36
Jan-11 49
Feb-11 65
Mar-11 181
Apr-10 278
May-11 368
Jun-11       133
Total for Year 2330      

Reg's performance was better than predicted. The original estimate was for 2100 KWh for the year. The total achieved (2330 kWh) represents an 11% increase on what we were expecting. The good weather in April and May undoubtedly helped.


Figure 1 shows the production figures in bar chart format.

Figure 1: Monthly KWh Production
Graph of Reg's Monthly KWh Production The bar chart shows that June was the best month of the year for energy generation. During the 30 days of June* 409 kWh were produced, an average of 13.6 kWh per day. The best single day for production was on the 3rd June 2011 when 20kWh were produced.

*See Table 1 for explanation of calculation of figures for June.

The lowest month for energy production was December 2010, with an average of only just over one kWh per day. Reg did not produce any electricity on six days during December. Not surprisingly the worst spell for nil production was concentrated around the shortest day (from the 20th December to the 24th December Reg did not produce any KWh). Short days, bad weather and the shading of the willow tree all combined to drastically reduced Reg's capacity to produce electricity at this time.

We were very relieved that the system more than met our expectations for annual energy production. Much of our concern about how viable the system would be was based on the effect of the tree shading on the panels. The tree is very large and during the winter months the shading effect on the roof begins soon after 1:00 pm. Fortunately, the sun's path through the sky during the spring and summer means that it is high enough for much of the sunlight to avoid the tree.


Posted by RugbyFoE | July 2011 | Reg

Carbon Savings and energy savings

The estimated CO2 saving for the year, figures provided by our energy provider, is 1.3 tonnes. This is pleasing as we have exceeded our expectations with this figure.

It should have been easy to work out how much energy we used directly from non-renewable sources, e.g. as purchased from our energy supplier. However, this has not been the case as our electric meter began to run backwards after Reg was installed! The meter reading was falling as a result of the input going in to the system. It took our energy company several months to fit a new meter that did not run backwards when the sun was shining. This has made it difficult to work out the amount of electric we used from the national grid during this period. However, it has been possible to make estimates for the annual kWh bought from our supplier.

From the fitting of the new meter in September 2010 to mid-June 2011, 902 kWh were recorded. This is approximately a period of 9 months, and so an estimate for the forthcoming three months is necessary to calculate the yearly figure. Estimated from our current average daily summer usage (2.44 kWh), the remaining three months' usage would be 186 kWh, giving a total of 1088 kWh for the year. We can check this on the new meter's anniversary in September.

Posted by RugbyFoE |  August 2011  | Reg

* * * August 2011 Update * * *

We have now passed 3000 kWh production (by mid-August - approx one year and two months) and have received total payments for the FiT of over £1100 for the first year's consumption. This is helping to pay back our capital expenditure which will, hopefully, take slightly less than 13 years.


Posted by RugbyFoE |  September 2011  | Reg

From the fitting of the new meter in September 2010 to end of September 2011, 1102 kWh were recorded. The average kWh consumption per day for this period of just over one year is 2.80 kWh. If the 2.80 kWh per day is multiplied by 365 days then the yearly purchase of grid electric equals 1022 kWh.



Annual Carbon Savings and energy savings

Continuing with our assumptions, our yearly purchase of grid electricity, pre-Reg, was 1780 kWh (2009/2010). This has now fallen to 1022 kWh and very roughly this means that our annual consumption of grid electricity has fallen by 43%. Solar panel installers normally work on the basis that there will be a saving of around 50% on electricity purchases. The reason, we think, that we haven't reached the 50% level is that we were already low users; at least 50% below the national average (although what is meant by the national average?!). At this level of usage it is more difficult to achieve high levels of savings.

Taking this a step further, if our overall electric consumption has remained at 1780 kWh, this means that 1022 kWh is coming from the national grid and 758 kWh is being supplied by our own system. Going on, if our system has produced a total of 2330 kWh and we have used 758 of them, then our export to the national grid is 1572 kWh. If we had an export meter fitted, as well as the solar production meter, we would be able to work out more easily what we are using and what we are exporting.

However, we were discouraged from acquiring an export meter by the high cost of purchase and maintenance.


Table 2: Generated, Used & Exported KWh

      Total Generated by Panels
2330
Used from Grid Used from Solar Exported Solar
1022 758 1572
Total Consumed      
1780


Summary

  • We have had a lot of fun keeping an eye on how Reg has performed during the year.
  • We have found that it is an interesting topic of conversation (not just for us!).
  • We have saved 1.3 tonne of CO2 through the installation and use of the panels.
  • We have learned that the system actually works. To produce 2330 kWh of electricity in a year, with our own little power station, is no mean feat. This is proof positive that the technology works
  • We have become even more energy efficiency conscious and we are constantly looking for new ways to reduce energy consumption.
  • We have earned approximately £982 from the FiT
  • We have saved approximately £85 on the purchase of electricity from the grid.


Posted by RugbyFoE |  October 2011  | Reg

* * * September 2011 Updatee * * *

We have now passed 3350 kWh production (by 30th September - approx one year and three and a half months) and have received total payments for the FiT of over £1100 for the first 12 months production. This is helping to pay back our capital expenditure which will, hopefully, take slightly less than 13 years.

As mentioned earlier, we have experienced major tree-shading problems from the outset. However, there has been a significant development with regards to this problem.  The large willow tree, situated immediately outside of our property, was extensively damaged due to high winds we experienced in the middle of September.  Emergency repair work, authorised by Rugby Borough Council, was followed by a major pollarding of the tree.

Photo of Willow Tree taken by JJ     Photo of Willow Tree pollarded taken by JJ
We now have no shading problems and we have seen an improvement in Reg's performance during the afternoon since the work was carried out. We have been advised that the tree will grow rapidly but we are currently enjoying higher levels of production post 2:00pm. The recent glorious weather has been an influence, no doubt, but our data logger shows that at least two to three more kWh are produced in the afternoon when conditions are right.





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