Aug 15, 2018

Seven perfect steps to saving energy in an EV owning home

Straight talker James Allston gives you the clear path to an optimised home

Chatting with friends recently, the conversation turned to household bills. Energy bill shock gripped the discussion. One friend was in disbelief over the price she paid. She commented she’d rather spend her hard-earned money on things she loved doing other than paying bills.

As an energy expert, I started to enquire what she was going to do about it. To my surprise her response was: “I don’t think there’s much I can do”! Her expectation was that reducing energy costs was time consuming and difficult. Not so!


Here I give you the same advice I gave her, 7 simple steps I have learned to save energy and money:

  1. Get the best tarriff

  2. Optimize time of use

  3. Take more control

  4. Tune your home

  5. Upgrade your appliances

  6. Upgrade your home

  7. Buy solar

I have found that by taking these actions in the correct order optimises the savings and avoids wasted effort. In essence, I recommend:

  • Do low or no cost measures first

  • Do the easiest stuff first

  • Make investments in energy saving equipment at the right time

  • Put your savings from the easy stuff towards larger energy saving investments

What’s different about this blog?

There are many excellent existing websites that give great advice, like this one and this one and this one. These can be used to gain information on every energy efficiency measure under the sun, BUT – they never tell you the best order to implement their advice.

Most people ask: What do I do first? Where are the easiest wins? Well read on…

Here are our simple steps you can follow

1. Get the best tariff

If you have not changed tariffs in the last 12 months there is a high chance you’ve rolled onto a variable tariff and you’re paying around £300 per annum too much for your energy.

Charging your EV at night on an Economy 7 tariff can save you up to £100

Because you’re an EV driver an Economy 7, Economy 10 or Time of Use (TOU) tariff is most likely the best for you. An Economy 7 tariff gives you seven hours at night of cheaper electricity. An Economy 10 gives you an additional three hours at a cheaper rate in the afternoon, but watch out for the standing charges which are typically higher. A number of sites allow you to compare the prices of different tariffs and suppliers - take a look here or here. That said, these sites don’t help you to compare standard tariffs with Eco 7 tariffs, nor do they take into consideration your actual usage between night and day (unless you already have an Economy 7, 10 or smart meter).


To help, we are developing a new feature in our Evenergi app that will use your actual energy data to determine the best tariff for your home and EV.


[Note: swapping from standard to Economy 7, 10 or TOU will involve swapping to a new meter. This may involve a small cost but will likely be worth it.]


2. Optimize time of use

If you’re on an Economy 7, Economy 10 or TOU tariff then you’d better use it properly or you’ll be worse off than going on a standard flat rate.


This means charging at night, setting timers on appliances and generally avoiding discretionary energy use during the “peak price times”. In other words, charge your EV and use appliances like the dishwasher, washers and dryers at night during your off-peak period. This takes advantage of the cheapest electricity available for purchase. Start and stop times for your economy tariff will depend on where you live so be sure to find out those times.

3. Take more control

Automating energy saving decisions is one of the best ways to save without selling a kidney to do it. It takes the time and guess work out of cutting down electricity use. There are many smart devices on the market that help you take control. Electricity use can be reduced through using electricity when you need it and switching it off when you don’t. So, if you have forgotten to turn off the heating when you have gone out a remote-control app can help.

Humans aren’t robots when it comes saving energy and nor should they be, especially when automation is an option.

Here are a few devices to think about. When choosing, always consider the one that has the features that you find easy to use and best suits your situation.

  • Nest Learning Thermostat  - comes with smart controls for heating and hot water and learns your routine.

  • Smart EV chargers – remote management of your charging is possible with smart devices. Only get this if your car doesn’t have charge timer controls already, most do.

  • Standby killer powerboards – automatically turn off a set number of sockets when a key device is turned off or a remote switch is flicked

4. Tune your home


Don’t let half the energy used to heat your home escape through holes in your home. A very effective way to save energy is to stop the heat leaking out by sealing or draught proofing all cracks around doors and windows. This will also keep the house cooler in summer. Plugging the holes comes with little expense but your body and pocket will feel the difference. Draught proofing kits are cheap to buy from hardware stores. If you want to find every last breeze in the home, walk around with a burning stick of incense on a breezy day and see when the smoke blows away from a crack in the wall.


Also, get the most from your existing heating. Install a radiator reflector panel or booster to help direct more heat into the room rather than the wall behind. And don’t let the radiator be covered by curtains.


Check the lagging on the hot water pipes. Insulating pipes can be done cheaply to great effect. Also flush the system once a year to make sure there’s no air in the line.


Unplug unused devices. Give a little thought to the critical appliances you use. Disconnect those you don’t.

Appliances left plugged in and not used can collectively costing you £200 per year just on their standby mode.

How you manage your home heating also helps. Close the doors between heated and unheated rooms. And close the curtains to avoid heat escaping out the window. On hot days make optimal use of opening windows to cool the house. Especially during a hot spell, use the cool night air to cool the house down.


5. Upgrade your appliances


From here on in the process requires significant investment so focus on what actually makes a difference. That means address large energy users that have big saving potential.

For example, there’s no point replacing an appliance you never use or doesn’t use a lot of energy. And generally, the most cost-effective thing is to only replace an appliance at its end of life. But straight-up, we believe the biggest wins for appliances are:

  • Swapping out a vented tumble dryer to a vastly more efficient condensing dryer can save around £35 per year.

  • OLED (Organic light-emitting diode) TV’s saving around £30 per year over LCD TV’s (quite aside from the viewing benefits of UHD!)

88% of tumble dryers in the UK have a poor C-level energy rating or worse.

For everything else, we’d suggest not replacing something that is working to make an energy saving, unless the appliance is very old.


But when the time comes, Sust-it is a great resource for finding the best energy efficient appliance to suit your needs. Or also try Digi-label. What you’re looking for are A+++ rated devices.


Also join Evenergi’s Charge Together program which will run group-buys for high efficiency appliances.


6. Upgrade your home


Next, make changes to your home. The biggest wins in order of cost are:


Lighting - upgrade all lighting to LED is the cheapest measure here. It might feel a bit mad spending £5-10 on a light bulb when options for under a pound exist, but it is definitely worth it. Not only will each globe save 80% or more over a traditional filament globe but they also come with lower maintenance. LED’s have a life span of about 20 years versus 2-3 years for a traditional globe.

At around £300 per year, heating your home is likely to be your biggest single energy expense. You’ll want to make sure it’s done efficiently.

Insulation - After years of insulation programs in the UK, only about 30% homes still have insulation potential. But if you’re one of those homes in the 30%, installing insulation in roof, lofts and wall cavities provides a barrier to heat loss and save a few hundred pounds in heating per year. Effective insulation also comes free with added health benefits of less mould and damp.


Boiler Replacement – Whilst boilers are high energy users, changing just for efficiency will not generally pay for itself. Replace your boiler to the most efficient condensing boiler only at end of life (i.e. after 10-15 years of use).


There are other things you can do but they are expensive and probably won’t save a lot of energy.


7. Buy solar


Once you’ve done all of the above, then it’s time to think about a solar PV system.

While solar will deliver the biggest cost savings, there is no point overinvesting to power an inefficient home.

Before purchasing, consider the suitability of a solar PV system in your location. Orientation and shading from trees can be a restriction to efficiency. Check that your house and especially the roof is suitable. In general, it's best to get a few quotes and some expert advice before making this step.


Also have a read of our blog on Solar and EVs, as there are lots of ways to optimise your return.



So there you have it, the 7 steps to perfectly optimizing your home's energy use and avoiding the time wasting stuff. Let us know how you go!

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Home: located in the South East using 4300kWh p.a, assumed average Class 1 profile (from Exelon) | Petrol Car: Mid-sized car with 8.5L/100km efficiency driven 7900 miles per year | EV: Nissan Leaf 30kWh driven 7900 miles per year, 80% home charged | Solar: New 3.5kW solar system costing £4550 | Feed-in Tariffs: The current rates for Feed-in Tariffs. i.e. Generation FiT: 4.07 p/kWh and Export FiT: 5.03 p/kWh | Tariffs used in comparison: Flat rate tariff: Unit rate: 11.86 p/kWh Standing charge: 23.65 p/day Economy 7 tariff: Day unit rate: 12.91 p/day Night unit rate: 8.13 p/day Standing charge: 23.65 p/day
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