Generate your own power
Posted on Nov 23, 2007 under Electricity, Heating, Lister engines | 17 Comments
I dug up some old electricity bills the other day to check how much juice we have been using over the past few years. I was shocked by the numbers I found, we use about 10500 kWh a year which equals a constant load of (10500 kWh / 365 days / 24 hours =) 1.2 kW or 1200 Watts. The power usage itself isn’t the shocking part, considering we use electricity to cook on, have a bunch of other appliances that are used regularly and a few tropical aquariums, one of which is a saltwater aquarium which has some quite powerful lights and pumps. What did shock me was to see the total money spend on electricity. With a kWh costing about 24 cents, the total yearly cost for our electricity usage ads up to 2.5 grand (that is Euros, which equals about 3,700 US$!!!)
There are better things to do with that kind of money but we still need the electricity. Sure, we can probably cut down on usage, but quite frankly there are not a lot of electric comforts I want to give up. I will use an average of 1000 Watts of power usage to figure out what kind of power plant we need to build. If I take into account the small fish farm we might want to start, that adds another 1000 Watts.
I’ve already ruled out solar power because the up front costs will be too high. I do want to tap into the power that the sun delivers for free, but I will use that for heating instead of electricity generation. Wind power is another free source, but since it depends on the weather conditions I’m not too keen on that either. I will probably experiment with wind power in the near future but for now I need a better, more constant, source.
I am having a closer look at Lister-engines and the more I read about them, the more I like them. A Lister CS (cold start) engine is a diesel engine that can deliver great power for very little cost. These engines are build to run for decades, I’ve read about some that have been running 24/7 for over 40 years! And the required maintenance is very low. These engines run at low speeds of 600 – 1000 RPM, making them less noisy than regular diesel generators.
Running an engines like this hooked up to a 10 kW power generator for about 5 hours a day would be able to cover my total power consumption. The heat generated by the engine can be fed back into the central heating system. Using the generated heat would be another big money saver considering the huge increase in oil prices, currently at $95 a barrel vs. $52 per barrel in January! The oil price does not affect the running cost of the generator as it can run on waste vegetable oil, which can be collected from local restaurants for free. The restaurant owners normally have to pay to get their used cooking oil disposed of.
Since the electricity generated by the generator would be somewhat constant while it is running and the usage has spikes as appliances get turned on and off, a buffer is needed to store the generated power, so it can be used at times when the generator is not running. One way to store your electricity is in batteries, but since most homes here are connected to the electric grid, we can just use that! Solar systems are often hooked up to the grid like this, by using a special electricity meter you can have the meter run backwards when you generate more power than you use. If we feed enough power back into the grid we can start sending bills to the power company, much better than receiving their bills!
