We’ve already covered easy ways to save money on electricity and reduce your carbon footprint. But what comes next? Is it time to consider solar power for your home? Or at least a solar hot water system? Well, maybe. But first you’d be wise to do a home energy audit. Figuring out how much of your gas and electricity bills comes from which appliances or activities can help you decide how much more you can reduce your energy use.
And figuring out your energy needs is essential to deciding what size solar installation you will need, if that’s the path you want to follow.
On this page:
- A simple home energy audit
- A more complete energy audit
- More ways to reduce your gas and electricity bills
- If you have them, look at your last 12 months worth of gas and electric bills. This can not only give you a baseline to work from, but can show you how your energy use goes up and down over the year. You can also see exactly how much money you are spending and start to think about how much you can save.
- Find your electricity and gas meters.
- Write down the time and day and then the reading on each of the meters.
- After a week, check the meters again, at about the same time of day. NB Try not to make changes during this week! The idea is to get a base line reading from which you will reduce your energy use.
- Subtract the second reading from the first one to get a baseline reading for your weekly poweruse.
Having your power bills for reference is useful, but it’s much more motivating to track your power use on a weekly basis than monthly or quarterly. However, you also need to be conscious of the time of year, and whether your energy use is typically changing at that time of year anyway.
Now, with the simple audit you have a place to start and can skip straight to reducing your power use, but it can be even more useful to do a more complete energy audit. This will tell you what is using the most energy in your house and how you can reduce your energy use most easily.
In most areas you can have someone come in, either from your utility company or from your local government or an independent consultant, to do this for you (often at no charge), but you can also do it yourself. You will need to buy a power meter. You plug this into your electricity outlet and then plug your appliance into it. It will tell you how much power is being drawn, and you can enter the price of electricity to find out exactly how much each appliance is costing you. In Australia you will pay about A$20-$60 for a power meter, or this one on Amazon is US$21.89 (reduced from over $50 though).
Be thorough. You need to go around the house and check every appliance, including those that are turned off! You might be surprised by the results. Don’t expect to do this all in one go.
To check how much power is being used by items directly wired in, you will need to turn off or unplug all other appliances at the power point (in Australia each power point has an on/off switch, but I know that in America that is not standard), and then record what is happening on your electricity meter.
I read this great example of an electricity audit yesterday. It is a very detailed account. That link will be particularly useful if you have a pool.
Most of this so far has been about how to save money on your electric bill. So what about your gas bill?
- Whether you have gas or electric hot water, reducing your hot water use can result in significant savings. Standard electrical hot water systems can account for up to a third of your electricity bill. Even if you have gas hot water, it can still use a lot of energy. Reduce your hot water use by:
- Fixing leaky taps
- Reducing your shower length – try using an egg timer
- Installing a water saving shower head
- Washing cloths on a cold wash cycle.
- You can also reduce the energy used to power hot water. If you have a hot water tank, check if it is warm to the touch. If so, it is losing heat and wasting energy. Wrap it in an insulated blanket. You can also insulate your hot water pipes.
- If you have an instant hot water system you are already saving a lot of energy, but consider running your shower with the water a degree or two cooler.
- A gas boosted solar hot water system is the most energy efficient system available.
The other big use of gas is usually on heating your house. And if your house is heated by electricity then this is an important area to save money on your electric bill. We’ve already covered some ways to reduce your energy use for heating, such as plugging drafts, in an earlier post.
Once you have got those basics down, the biggest thing you can do to reduce your heating bill is probably to insulate your house (unless it is already well insulated). Be aware that over time insulation degrades, so just because your house was insulated 20 years ago, doesn’t mean it won’t need a top up today.
About 25-35% of heat loss is through the ceiling and roof space, with 15-25% lost through the walls and 10-20% through the floors. Conveniently, getting your ceiling insulated is usually the cheapest of the three options, so if that’s all you can afford, it’s a good place to start. But getting wall insulation will also make a big difference to your heating bill.
About another 15-25% of winter heat loss occurs through “air leakage”, so getting those drafts plugged is really essential. The Your Home Guide to Passive Solar Heating has an excellent section on how to prevent heat loss.