For at least a couple of days, climate change has been back on the agenda with the protests happening in London by Extinction Rebellion. The coverage has fallen into the usual “adversarial” pattern: weighing the protestors’ points against the need for people to travel, or asking whether it is hypocritical that some protestors arrived by car / train / plane. Fundamentally, the point has been somewhat lost, but it makes me think anyway.

The crucial point that I think we should take away from the protests is that we, collectively, are not doing enough. Personally, I’m not doing enough. And it really is time to change that. So, here are my thoughts about energy consumption for starters – it would be great to hear what other people are thinking about and doing, too.

Energy consumption is a relatively easy place to start because it’s quantifiable, and there are a variety of options for people to reduce their impact. However, while I did monitor our electricity consumption for a while, I’ve fallen out of that habit – so, job number one is to actually quantify it again.

The trouble with gas

Like many (most?) households in the UK, our home is dual-fuel: we have electricity and gas. However, unlikely some homes, we only have a single appliance – the gas boiler for hot water. Gas isn’t a renewable resource, although you can generate it sustainably – however, that seems more trouble than it’s worth. New homes in the next ten years are going to be built gas-free, and that seems the right direction to go.

We do have a gas fire in the lounge, which is currently out of use. We had been looking at replacing it: it seems to me that we should replace it with an eletric heater, as part of the commitment to avoid gas. We should also look to replace our boiler – when the time comes – with something non-gas. I probably wouldn’t go so far as to rip out the pipework, though.

In the meantime, we can change our energy supplier to one who only supplies renewable electricity or sustainably-sourced gas. There are many of them on the market now; our current provider sources only up to 25% renewable/sustainable. So, we can also make the switch to one that supplies 100% renewable/sustainable.

Electricity usage

As I mentioned before, we haven’t been tracking much of our energy usage. The new SMETS2 smart meters are now being installed in our area, so it makes sense to ask to move to that. These meters track and report usage automatically – no more meter readings! – but also ensure that you can see what energy you’re using.

Switching provider to a renewable-only supplier is a decent start, but obviously we should also be looking at other things: either reducing our consumption, generating our own electricity, or (ideally) both.

Reducing usage

Now, our heating system is somewhat smart (Tado) and that has reduced our usage, but that’s still gas-powered for now. Next after heat, the big offenders in terms of electricity usage are:

• white goods (fridge/freezer, washing machine, dryer, kettle, dishwasher)
• lighting
• cooking
• TVs & computers

We don’t have any power showers installed, and a good chunk of our lighting is already low-power LEDs. Most of the appliances are relatively new so it doesn’t make sense to replace them; they’re also efficient (as these things go, anyway). There isn’t an awful lot of scope here to change things massively, it seems.

Generating

You can generate energy in a couple of different ways. I’m going to discount home wind power, because that doesn’t seem to be viable (at least for us).

Home water heating is a popular one. You stick some panels on the roof, route water through it, and the solar energy heats the water. For me, this doesn’t look terribly worthwhile (again, at least for us): there would be a lot of pipework alteration, it doesn’t capture a huge amount of heat. It’s better in the summer, when you least need the hot water.

Solar photovoltaics look a much better bet. For one, the energy you generate can be put to use in a few different ways (not just heating). You can also store it in a more efficient way. Tying in some solar panels with something like a Tesla Powerwall comes in at around £8k for the battery and another £8k for the solar installation. If you’re a regular household paying something toward £1k/year for energy, obviously that’s going to take some time to recoup – but the cost of energy only seems to go up, and PV keeps getting cheaper.

Changing Systems

Once you have some on-site generation, there are a couple of different ways of making use of it. One thing I’ve realised is that the majority of things plugged into our power are DC-powered: that is, a lot of our electronics are 12V devices. This means there’s some rectification of the incoming AC power, and step-down from the 230VAC supply.

Now, AC makes a good deal of sense for transmitting electricity. Also, it does make a few other things easier – e.g. even physical switches are going to be less prone to arcing. However, having a home electricity circuit run in DC could have some serious benefits.

Direct circuits for DC lighting as an example, and maybe combined data / power wiring (based on Power-over-Ethernet?) would be a big boon for the Internet-of-Things home.

One of the downsides of DC circuits is that you tend not to be able to run high voltages or significant power (without causing lots of other issues), but that would then help push devices towards lower electricity consumption overall.

I have seen some systems where a DC-based PV array can feed into batteries which then feed into electric vehicle charging. That seems a pretty smart set-up to me – potentially expensive, but much more efficient.

Conclusion

I could have switched to renewable sources many years ago, and it’s about time I did that – I should be spending money on the types of product I want to support.

There don’t seem to be a lot of opportunities to reduce consumption significantly without a. replacing working goods or b. switching power sources, but generation of electricity must be a smart thing to do.

I haven’t spoken at all about offsetting. Carbon offsetting is deeply problematic in a number of ways, but I’m also going to have a look at putting money into renewable generation schemes and such-like – that would definitely help reduce carbon usage.