Starting on the Numbers

Before we can do any of the maths on how much energy we are using at the moment, I need to understand the best units to work in. Luckily my daughter, Devi, and son in law, Matthew, are on hand to make up for the physics lessons I failed to follow at school.

It seems the basic unit of energy is the joule. It’s not a large unit, so we will be thinking in kilojoules and megajoules. Then when thinking of appliances and systems that use energy we need the watt. This is the rate at which the appliance is using the joules. 1 watt equals 1 joule per second. So now to turn this into actual cases:

A hundred watt bulb will use 60 x 60 x 100 joules in an hour. That’s 360 kJoules. Since the electricity meter measures kilowatt hours that’s the equivalent of a tenth of a kilowatt hour. And at around 6p per kilowatt hour, that light is costing us 0.6p for every hour that it’s on.
The television is rated at 67 watts, so it takes about .07 kjoules an hour, which costs us about 0.4p for every hour of viewing.
And the 1 kilowatt electric fire takes 1 kWatt an hour, costing us 6p.

And by the way, the appliances that are left on standby are using around a third of the power. So the television may only be costing 1 or 2p for an evening’s viewing, but it costs an additional 3p for the rest of each day. And that applies to the set-top box, the two screens and the several other boxes. In terms of computers left on, those are figures to find out…

When it comes to oil, there should be a conversion into watts that we can find. But before that there is the simple measure of how many litres of oil we are using, since avoiding burning fossil fuels and producing greenhouse gases is our main concern. But the efficiency of the boiler and the insulation of the house do come into play, since if these were improved we could achieve the same level of comfort for less carbon produced. In this regard, the EU energy efficiency grades are apparently the thing to look at. Anyway, insulation may be boring but it remains the best first way to improve matters.

Calor gas for the cooking is similar, as it the petrol used in the vehicles.

Matthew also introduced me to Good Energy (www.good-energy.co.uk) which sounds like just what we need. It will supply electricity at a higher rate, but guarantee that it’s all produced from renewable sources. For Hedgerley Wood they will charge 7.85 per KWh plus a standing charge of 12.83 per day. That immediately suggests (and to him as well as to me) that it might be better to heat the water with an immersion heater ultimately powered by GE’s renewables, but to use a smaller amount of oil. Need to check on the logic of this.

Clearly GE can’t at the moment be the answer for everyone, since they don’t produce enough for the needs of the whole country, but the sense is that every household that joins helps them expand their capacity.

They also have on the site a very good first indication of carbon dioxide emissions. The average household, they say, produces 10 tonnes of carbon dioxide a year. And a small car traveling 6 miles produces 1.5 kg.

In the case of Hedgerley, switching to GE for our electricity would, by itself, save around 2,070 kg a year. This is based on the fact that 1 KWh produces 0.43 kg of CO2. When I get back to the electricity bills I should be able to check out our current carbon emissions from electricity.

The other great advantage of GE is that they will buy back electricity that we produce locally. According to the first descriptions of home generation on the site it looks like a much better option that storing locally any energy we produce.

That leads to the question of how we could produce it. The sites to start with (tomorrow) seem to be:
British Photovoltaics Association – www.pv-uk.org.uk

The Energy Saving Trust – www.est.org.uk

If we start with solar it seems that heating the water is the best, since energy is lost every time you convert between different types. Of course with our amount of sunlight it will only heat the water to a certain level, but that will make the final burst of heating required smaller. Beyond that, how to produce electicity is the next thing to research. We need to know whether the same panels can do both, what it will all cost and what we do about all those water pipes during the freezing months.

For wind energy I’ll have to wait to tomorrow to continue the research. I am after all on holiday and the internet connection here is pretty ropey.

Starting in Sri Lanka

Colombo seems to be a good place for making resolutions. Twenty years ago I was here and decided to become a vegetarian after reading Gandhi. Now I’m inspired by Anuradha’s idea for a new way to campaign on climate change at OneWorld: seeing it as a commitment to the coming generations. That led us to discuss how we can personally take the issue more seriously and how we can try and align our own life at Hedgerley Wood to these values.

So we’re starting with three aims: to reduce our use of fossil fuels, to save money and make our life more sustainable in retirement, and to record the process in case it’s helpful for other people. So I’m starting with this blog and pictures and will maybe extend to a video diary in due course.

Of course we could be much more radical: move to Sri Lanka, stop commuting to work, live off our own produce, build earth toilets… But in the first place I don’t want to do this and, secondly, it seems unlikely that the majority of people in the UK or the US would want to either. The relevant challenge – at least until things get a lot worse – is to see how far we can go in reducing the negative impact of our current house, jobs and lifestyle.

It seems like the place to start is with a baseline survey of our current energy use and where that energy comes from. That’s both directly in the house and indirectly through our other activities. For that I’ll have to learn a bit about units of measurement of energy.

On the direct side the rough energy inventory I suppose we start with is:
• Oil – for heating, hot water and the pool
• Electricity – for light, some heating and a lot of gadgets
• Gas – for cooking, but very little
• Petrol – for the car, scooter and lawnmower
• Logs for the living room fire.

Indirectly we have to look at the travel we do for work and for leisure.

On the other side of the equation is the positive impact of the woodland round the house. I don’t know how fair it is to count this since we have done little more than buy the five acres and not cut down the trees. However, it will be interesting to know what the contribute in terms of taking up carbon dioxide each year.

Then to begin to research the subject I guess a good starting point would be the Centre for Alternative Technology. I first look at www.cat.org.uk is a bit disappointing, although there is a good list of books on alternative energy. Probably best to go down there, look at working systems and talk to the experts about what really works. A lot of the solar and wind machines they list are at the level of toys and we need to find where the heavy duty stuff is.

It feels as though when it comes to solutions we should start with the issue of storage. However we generate the renewable energy it will have to be either stored or sent to the grid when it’s not being used. So this is a first thing to sort out. I’ve read something about an option of storing in the form of hydrogen, which sounds interesting if a bit daunting. Certainly what I have seen of solar in India suggests that conventional batteries are not really the answer. Even with their amount of sun and pretty large collectors on the roofs, they still need what seems like small rooms full of car batteries even to power a computer and a few lights for 3 or 4 hours. Anyway we need to do the calculations.

Then, still without knowing much at this stage, it seems that after the first phase of survey and research, we could begin on just a few parallel tracks by deciding:
• What form of storage to go for
• What first form of renewal energy to try (maybe solar for hot water)
• What changes in lifestyle could make an immediate difference (not using the pool).

I don’t think we are going to expect to balance the books in the early years. It seems many of the alternative technologies take many years to pay off. But this could suit us well, since we are in a position to invest now in order to have a more economic way of life when living on a pension in ten years’ time.

Now it feels very good to have created the first blog entry, because I hope this will be a great way to link with other people working on similar projects.