1 year of solar panels + energy costs…

It’s been 1 year since we had the solar PV panels installed on the front roof of our house. It’s been a really inspiring and life-changing experience in many ways and we’re more aware now of how much energy we’re using and what times of day it’s best to use certain energy-intensive appliances.

So, over the year, the panels produced nearly 1250 units of electricity, which will give us around £540 from the feed in tariff (at 43.3p per unit) and equaled 43% of the electricity we used.

The types of fuel we’ve been using are wood, gas and electricity. For gas, there is an equation which the gas companies use to convert the metric units of gas which is burned in the boiler or oven/hob to a KW/h ‘unit’.

units used x calorific value x volume correction / conversion to KWh = gas used in KWh

This is… X units x 39.3 x 1.022640 / 3.6 = X KWh

This allows you to compare the actual energy that is used for gas and electric, in a comparable unit, in this case KWh. This is a bit geeky but the figures below (even for what turns out to be our very low usage) are pretty big, especially when the gas and electric consumption is compared with what our solar panels are generating. Here are our figures for the last year…

(01/01/2011 to 01/01/2012)

Gas = £249.18 or 3371 KWh

Electric = £374.52 or 2923 KWh

(01/02/2011 to 01/02/2012 – our 1st full month generating was February 2011)

Solar panels = £540 (income) or 1248.9 KWh

So, £623.70 spent on gas and electric for the whole year. Add to this the £360 for the 6M3 of firewood for the space heating of the living areas gives £983.70, which is the total spent on fuel/energy for the year.

The total in energy terms (KWh) was 6294 for gas and electric. I’m not sure how to work out the KWh provided by the wood though??

From the cost of £983.70, the income from the solar panels should be deducted (£540), giving a grand total spent on energy for the year of £443.70!

Two really important issues come out of this. The first is the comparison of KWh totals for generated and used, as follows.

Total generated = 1,248.9 KWh

Total consumed = 6,294 KWh

There’s obviously a bid difference there and even with the solar panels, with the consumption roughly 5 times more than the generated (or even more if you add in the unknown energy value for the wood). Solar panel efficiency has got a long way to go before it’s able to claw back some of this difference.

The second thing to highlight is the ‘average’ figures for 3-bed semis, which all the price comparison websites use for their standard figures. These are their figures for consumption per year.

  • Average electricity usage of 3,300 kWh for standard single rate electricity that’s averaged across all regions and
  • Average gas usage of 20,500 kWh per household

Assuming 8p per KWh unit of gas and 10p per KWh unit of electricity would give…

Gas: £0.08 x 20,500 KWh = £1,640

Electric: £0.10 x 3,300 KWh = £330

Combined total = £1,970

If this total figure is used as a comparison, our total of £443.70 is amazing. This is 22% of the average and i’m proud that all the combined features we’ve installed and the way we live has led to this figure. It makes all the chopping of the fire wood much more appealing!


Jelly batteries…

Safer, lighter and more sustainable – the short-term future of battery technology is nearly here.

This BBC article highlights some of the possibilities, including more efficient electric car batteries and lighter laptops. Certainly the electric cars technology jump will make a big difference and hopefully lower the cost to efficiency ratio. At the moment, the cost of an electric car is higher than people’s perception of the benefit that they will get from it (including far lower CO2 emissions and cheaper fuel bills). The costs need to come down and the benefits go up to shift people’s firmly entrenched views.

This will also hopefully begin the process of creating a battery which is capable of storing huge amounts of electricity for long periods, in order to allow the electrification of the energy supply, including the removal of fossil fuel based energy sources.


Solar power legal action…

Great comment on an article on the Guardian Website:

Solar companies take legal action over UK feed-in tariff cuts!


19 April 2011 7:54PM

Oh dear, this article has only been out for a couple of hours and already the luddite ‘Trolls’ who think they are informed and ‘climate deniers’ have come out putting their ridiculous opinions forward

So, just for their information to start with, a paragraph taken from a leading renwable energy publication after Greg Barker had trotted off to Germany to ‘learn lessons’ from their Feed in Tariff legislation.

‘It is quite curious that [climate minister] Greg Barker was out in Germany last month partly so he could come back and say: ‘Look at what the Germans have just done in terms of scaling back their reliance on feed-in tariffs.’ But what he failed to mention was that on the Tuesday at 12 o’clock while he was there, the solar sector in Germany generated more energy than the nuclear sector for the first time in its history. The lesson I got from that was there is an industry that has scaled back the feed-in tariff time when they have got up to a 12.1GW of solar capacity.

Then, I shall also repeat a previous blog for the Trolls benifit, concerning the moronic fiasco that Huhne and Barker have created by their personal malicious destruction of the UK Feed in Tariff legislation that now means the UK hasn’t got the slightest chance of achieving the 2020 EU carbon reduction directive that will result in massive financial penalties the will make the costs of any Feed in Tariff incentives look like peanuts.

Under 18 years of progressive and refined Feed in Tariff legislation in Germany the Target that Germany has for PV installation by 2020 from the 18GW today, YES 18 GIGAWATTS, is according to the BSW roadmap (Bundesverband Solarwirtschaft ; Association of Solar Industry ) is 52GW. Yes , I repeat, FIFTY TWO GIGAWATTS.

I think that is actually quite impressive, and of the UK? Well, I’m sure ‘Greg Barker; The Butcher of Feed In Tariffs’ can help on this target. As for land based Solar Parks, there are about 1000+ in Germany AT THE MOMENT. In the UK? At the moment? NIL, and by 2020? NIL

I actually bothered to have a look at Europe’s renewable energy installation programme 5 years ago and it was depressing to really suddenly understand how far behind Europe Britain is in renewable investment. If anyone is really that interested then go to Intersolar Munich June 8/10, the world’s largest renewable energy exhibition and be shocked.

We could have caught up and the legislation had been put in place with the 2008 Energy Act. It was looking good, however what had not been allowed for is prats like Huhne and Barker getting into power. If the UK does not get some intelligent life into Government very quickly the country really is finished.


Snow-covered power station…!

Well, the roof-top power station is hardly running at full capacity right now!

So far, since Friday 17th December at 1:30 pm, the whole array has generated 0.7 units of power. This is a massive £0.29 at the feed-in tariff rate of 41.3p / kwh (unit)!

Paul from Target 2050 has just come round to complete the installation check, before they can the funds for the grant money. He seemed happy with it, even though the panels are under 10 cms of snow! He did say that the panels generally make most of their electricity during the 6 months over summer, but it will tick over during the clear winter days (providing the panels are clear).

As you can see above, Paul also sent me a link to his own website which has various figures for his own PV system, over the years. Very interesting numbers in there and there’s also a fair bit of variation between the years for the same months.

Anyway, you can see the general pattern, so we’re looking forward to the Spring months where output should go up a bit.


Tumble dryer back in action…!

Ok, we’ve had the clothes dryer ‘fixed’. The transition from using the outdoor clothes line during the nice summer and early autumn, to the late autumn and early winter weather, was meant to be covered by the new covered rotary outdoor clothes line.

Well, it works a treat, even in cold and wet weather, but it takes something like 2-3 days to dry! This isn’t necessarily a problem, but it just takes longer to get through all the mountains of washing.

The system we started using is to hang the washing out for 2 days, then bring it in and finish it by the stove on the clothes horse. This really just warms the clothes and gets rid of the slight dampness. There has been a fair bit of rain recently so the clothes have just been hanging in moist air, therefore picking up some moisture.

So, this has been working fine but the tumble dryer has been brought into the mix to get through the massive pile of washing. Claire was at home this week and has done a great job in washing and drying the washing – now we just have to sort and put away the massive pile of clean and dry washing!

Anyway… The other part to this tale (apart from me going on about our exciting clothes drying system), is the small experiment with the dryer, before and after the guy ‘fixed’ the dryer. So, normal cycle before the guy came around took 4 hours and 30 minutes! Yes, that’s ages.

After the guy fixed the dryer (by basically just cleaning out the insides from fluff and lint), the same cycle took 2 hours. So by simply cleaning the dryer out, it more than halved the time it takes to dry the clothes. So the main point to all this is that by cleaning the dryer out, will save a lot of electricity and money.


New clothes drying system…

Ok, the new clothes drying system is finally decided on, after months of thinking about how to best dry our huge amount of washing! The whole idea is to ditch using the clothes tumble dryer, as it uses a fair bit of electricity, with the cost and environmental implications.

We produce a lot of washing right now, especially with the kids going through loads of clothes. We needed a system where we can dry clothes outside in any weather, given that outside drying is very effective. The outside moisture level is less than indoors + the wind is a key part of it.

I was trying to design a system of multiple hanging lines, to be fixed to the back of the bathroom, but this is a fairly restricted area and is good for the sun, therefore growing food! The side of the house would have been good, but given we’re hopefully getting the render done, this wouldn’t be able to go there either.

So, keep things simple, get a rotary clothes dryer with a rain cover! Thanks to our friends the MK’s for that! Lots of places sell these things and lots of good reviews.

This friend of ours has already switched over to the new system – she fed back that that a whole load was dried within the day and some more as well. You can also leave it over night with no worries. I left a load out yesterday on a standard clothes horse and it was dry by early afternoon.

The equation for working out the cost of the dryer each year is as follows:

Power consumption of dryer (in Kilowatts) X Electric cost per unit (roughly £0.09) X hours operating per week X 52 = annual cost (£) of running dryer.

We’ve got a grade A John Lewis dryer which is a condenser dryer with a heat pump, which recycles some of the heat and power. It was basically one of the most energy efficient models when we bought it and uses 1200 Watts. A lot of other models use around 2000 Watts or more. I’ve worked out ours, based on 5, 6 or 7 hours operating per week, as it varied a bit.

5 hours = £28.10

6 hours = £33.70

7 hours = £39.30

I reckon we were at roughly 5 hours per week, as it’s roughly 2.5 hours per complete cycle and there were maybe 2 of those per week (as an average over the year).

So, this could be anywhere from £50 to £200 for less efficient dryers (based on individual usage) + the cost of buying the dryer in the first place and getting it fixed every now and again. So, a new rotary dryer and cover will be roughly £70, but we’re going to sell our dryer for hopefully at least a couple of hundred pounds + we won’t be using the electric as much.


200m cooling tower in your backyard…?

This is one example of NIMBYism I can agree with…


A proposed 200m (!!) cooling tower reduced in height to 70m. Seems sensible and given that it will be a power station generating electricity anyway, the power the fans will use within the tower will come directly from the source of the power, which is the most sustainable method.

It must be bad enough living near one of these beasts but to wake up to a bulkier and taller (by some 130metres) set of towers would be terrible.