Archive for the ‘Energy’ Category
Anaerobic digesters are not new, the first one was built in 1859 by lepers in a colony in India and used to produce methane gas for cooking. Since that time the production of food and, in particular meat, has become an industrial process resulting in lakes of sewage that have left the countryside polluted and the air filled with a miasma that defies description.
With the growing problem of animal and human waste and the growing need for electrical energy it was only a matter of time before producing power from poo became commonplace. Why then has it taken until now for researchers in Denmark to prove that anaerobic digestion is the most efficient way to produce energy. After all Denmark is a huge pig producer and has had a problem with farm waste for many years.
The beauty of anaerobic digestion is it can work on a small scale, all you need is a constant supply of waste matter and some relatively simple technology. A search of the internet will find many DIY solutions although most are aimed at situations in the rural parts of third world countries. I just wonder how long it will be before a commercial poo powered generator comes onto the market and all the pooper-scooping becomes more productive pastime.
The average water consumption in the UK is 150 litres a day per person and research indicates fitting a water meter reduces this consumption rate by 10 to 15%. Well we have a water meter and use less than 100 litres per person per day, not that we do anything special to save water, other than watering the garden from several water butts.
Research has also shown that the average household uses 25% of its total energy consumption on water heating, that’s in the dishwasher, washing machine and the hot water tank. We must be a very unusual household because my calculations show hot water accounts for less than 10% of our energy use. Out of a total consumption of 12,600 kW a year biggest element is space heating at 8,500 kW, hot water accounts for about 1,050 kW.
This is the problem with averages they can mean absolutely nothing unless one understands the source data used to create the average. Just a few rogue figures can make the result pointless, a maths teacher once pointed out he had more that the average number of legs for men in the UK. You only need one man to loose one leg for the average to be less than two legs. I doubt there is an average household in the country, but then again, when ever did accuracy ever get in the way of a good story.
I can remember the supporters of nuclear energy touting the idea that this new technology would provide us will cheap, pollution free energy for ever. The visitors centre at Doonray in northern Scotland proudly boasted that nuclear fission was safe and economic. It was the way of the future and we invested in new generating plants around the country. The doom and gloom merchants were derided as Luddites. How different it is now.
Nuclear energy has been at the dirty end of the market for years. New power stations are rare although there is a developing view that we may have no alternative as renewable sources of energy seen unable to much impact on our needs. Nuclear power stations cost billions to decommission and sit as potential hazards for thousands of years. We have taken a natural material and converted it into a deadly substance. One that could see towns and cities closed for years due to the contamination from a dirty bomb.
It not surprising that the Irish Government want to see Sellafield closed. There is no doubt it has polluted the Irish Sea and parts of the English, Scottish and Irish mainland for years. It is a legacy from the past that would be best closed down. Unfortunately for the Irish and those who live in the shadow of the site commercial interests are proving more important than the environment and human life. Its another example of how we continually get the balance wrong and bow down to Mammon instead of ourselves.
Solar water heating panels have been appearing on roofs all around the area. Having done all the simple energy saving tasks (cavity wall and loft insulation, double glazing, new doors, low energy light bulbs, new boiler…) I decided to take a look at this, apparently popular option. For an average home they cost around £3,000 to install and have a life of some ten years.
So how much do you save during that ten year period? The average annual cost of hot water is just £80 and the annual saving these systems provide is about 60%. Allowing 5% inflation the total cost over ten years is £604. Take off the operating cost of the solar heating system and the savings over ten years are reduced to £377. The maintenance cost during the ten year period will probably exceed the net savings.
Investing in solar water has no financial benefit for the average household. Even the carbon reduction is relatively small at 500 kg a year. At most it’s an outward sign that the household is trying to make a difference. However, they probably still fly away on holiday, drive large vehicles, ignore food miles and indulge in other carbon heavy activities. Carbon hypocrisy is alive and well in our suburbs.