Now for the majority of people using green electricity is not an option. For the poorest in Africa and Asia burning wood and animal dung is the only available source of energy. These are valuable resources and burning them contributes to global warming. So what can we do until we can buy green electricity or make our own green electricity at a reasonable price? Well the answer is pragmatic and simple. Just use less electricity.

In winter this is a lot to ask. You cannot turn off the heating and sit around wearing five sweaters. You still feel cold and you get really demoralized. Recently, a lot has been written about using space heaters to save electricity.

It is true that turning down the central heating (so as to keep the average temperature in your house or apartment just high enough to stop things freezing) and deploying a space heater in your living area is a great energy saving idea. It is practical and common sense: just heat up the area that you need. Furthermore, being able to control the heat output of your space heater is a big energy saving improvement. The old style heaters had two settings on or off and the user went through a cycle of getting too hot and turning off the heater and then getting too cold and turning the heater back on. This is very inefficient and not comfortable.

Consumers pay for electricity in kilowatt hours (kWh). In the USA the price of 1kWh is 32% cheaper than the average price for 1 kWh in Europe. The average space heater needs between 1000 watts and 1500 watts. For arguments sake say the space heater uses 1000 watts. If you use the heater for 1 hour you consume 1 kWh of energy. The average cost for residential electricity in the USA in 2009 was 12cents. If you leave the heater on for 5 hours a day it costs 60 cents. For seven days of 5 hours per day you pay $4.20. For 30 days, you pay $18. That might not sound like a lot but that is just one heater. Wikipedia states that the average residential household in the states spends 32% of its energy bill on space heaters.

It is starting to look to me as if space heaters aren’t such a great idea after all. They cannot be that efficient if they use a third of your total supply of electricity. Compare this to a modern fridge (about 500 kilowatts) which needs to be on all the time!

The problem with space heaters is that they are still heating up too much unnecessary space. The concept of only heating a limited space is right, only the manufacturers of space heaters haven’t taken the idea far enough. Funnily enough the Chinese and Japanese have known this for over 50 years. It is stupid to try and heat a whole room. All the heat dissipates and is lost. You must trap the heat near your body to be truly efficient. And the best way to do this is using a kotatsu.

A kotatsu is a Japanese low table with a small electric heater fitted to the underside of the table. Typically, the heater only uses 500 watts, and even that much electricity is not needed to keep you and friends nice and warm. The secret is a blanket that is draped over the table and under the table surface to trap the heat. The blanket covers you up to your waist. Of course it is possible to slouch nearly completely under the kotatsu and get really warm. The only disadvantage is that you have to sit on the floor, so you need a nice thick carpet and pillows to be comfortable. I have my kotatsu set up so I rest my back against my sofa. I find this set up just as comfortable as sitting on the sofa, and obviously on winter nights sitting with half my body under the kotatsu table is far more preferable than shivering away on the sofa. Using the air-con heater is never an option because they burn your money at an alarming rate.

Most kotatsus come with a thermostat control to reduce and increase the heat. I use one every day in winter in Japan and I usually have the heat setting at about half capacity. That means 250 watts as opposed to 1000 watts for a space heater. That’s a staggering 75% saving on an average space heater! Over an entire winter that is a big saving in electricity and therefore money. This makes sitting around a kotatsu on a cold winter night with friends or family about the greenest thing you can do. And what’s more you have a table surface in front of you to rest your rice wine glass. And of course in the summer you just remove the blanket covering and you have a useful coffee table.

So there you have it. Using a kotatsu is easily the greenest way to stay warm, and the cheapest. You can buy a Japanese kotatsu for as little as $150 on ebay. The heat trapping blanket could be any blanket or quilt. A set composed of blanket and pillows costs $130 on ebay. In your first winter you will pay this back in the energy you save.

Bid on Ebay for a kotatsu

Bid on Ebay for a kotatsu cover and pillow set