Investing in Less Energy

The old Japanese house I used to live in -we got through 100 litres of kerosene a week in winter!

I’m really pleased to have another guest post for you today. My friend Mark Brierley is a certified Passivhaus consultant and blogger, so it was inevitable that I would ask him to write something for RetireJapan at some point. You can read more of his writing at his excellent blog, or stay tuned for two more guest posts from Mark over the coming weeks.
​

“How much do you spend on energy? The average family in Japan spends around 20,000 yen per month. If you can spend less on energy bills, then you will be left with more, since these monthly payments add up over the years. There are other hidden benefits that I will get to later.

For over ten years I lived in an old Japanese house where our monthly energy bills went over 30,000 yen in the winter. In 2011 we built a house to the German Passivhaus standard, and our bill now only goes over 10,000 yen one month per year. As well as this tangible financial benefit, our new house is much more comfortable.

The first thing you can do to reduce the amount you spend on energy is to keep track of how much you are using. UK-based energy writer David Mackay says, “Since I started paying attention to my meter readings, my total electricity consumption has halved” (p. 156).

Switching off, unplugging, and turning down appliances will save money without any cost. You can save by just filling the kettle with the amount of water you need, and since your refrigerator is one of the heaviest electricity users in your house, your habits opening the door can make a big difference as your bills add up over the years. There are many little things to do and they will make a difference, but you didn’t come here for a lecture on how to behave in your kitchen, and more importantly there is a limit to what can be saved by changing your habits. Little things do add up, but often they are still relatively small! Your habits are shaped by your environment, and the biggest energy savings can be made by changing that environment.

“An ounce of prevention is worth a pound of cure“

Buying more efficient fittings and appliances can reduce your energy bills, but this depends very much on what appliances you have to start with. Energy use of new refrigerators halves every five years or so, which means replacing an old one can save money on your bills. LED lights use around ten times less energy than incandescent bulbs, and last over twenty times longer, so it makes sense to change them immediately, unless you need to use the bulbs as heaters. LEDs use around 30% less energy than fluorescents, and will last at least twice as long. The savings you make on lights depends on how often they are used, so it may not make sense to change a light that you rarely use. If you need to replace a bulb in your house, then presumably you have been using it, and it already makes sense to replace it with an LED. The cost of LEDs is halving every three years, so even if it doesn’t make sense to replace your old bulbs now, it will do. Once you change to an LED you will never need to change it again.

While refrigerating and lighting are often your biggest electricity costs, a bigger part of your energy costs go into heating or cooling your house, and in both cases better insulation will reduce your bills. If you imagine your house as a leaky bucket, and your heater as water going into it, then reducing the leaks means using the heater less. Japan is not a world leader in insulation, so some of those buckets can be pretty leaky!

Since insulation is not free, there is a trade-off between how much you need to pay to install the energy saving measures, and how much cheaper your bills will be. You can divide the two and work out how many months or years it will take to pay back the installation costs, and this will give you an idea of whether it is worth it.

This decision, and in fact your whole energy efficiency strategy depends on whether you own the house you live in, whether you are planning to build a new house, or whether you are living in rented accommodation.

If you are renting, then it may only be financially sensible to make cheaper changes that will have quick returns on your investment. The tragedy with rented accommodation is that renters are responsible for the heating bills while landlords are responsible for the building’s energy efficiency. Although tenants usually do not feel responsible, it is often possible to make major improvements to rented buildings in Japan, but you may need to add a lost deposit to your improvement costs, and there is always a fear that the improvements will give your landlord an excuse to increase your rent, or if you do a really good job at renovating, they may even ask you to move out so they can move in!

And if you are renting you may only be planning to live there short term. If you plan to live in Japan long term, you may be better off getting your own house, although that is another topic.  

David Mackay’s book Without Hot Air is available in full online here: http://www.inference.phy.cam.ac.uk/withouthotair

Thanks Mark! Very interesting and practical advice. I’m really pleased we made an investment into insulation for our manshon -it really has improved our quality of life although we still have a long way to go. Will be looking at some appliances next (our A/C is about twenty years old!).

​Looking forward to the next instalment of investing in less energy and I will definitely be in touch when we take the plunge and build our own house.

What  do you think? Anything to add to Mark’s advice? Any questions?
​