The wonderful world of Flex-Tech

This month I want to talk about flexibility technology (or flex-tech for short). Flex-tech is one of the biggest enablers for homeowners to be more flexible with their energy and save money on their energy use. The idea is that an energy company (like Octopus Energy) or an aggregator (like enel x or Flexitricty) can use usage, price and weather data to intelligently manage your technology to save you energy, money and emissions. Sometimes you can even make money by letting them! This can be done on a really big scale if we aggregate the flexibility of individual buildings to local or regional scales, and this is often much cheaper than large, centralised solutions like a big battery.

But what kinds of technologies are ‘flex-tech’? Here are a few of the more common systems you’d find in the UK and some I’ve been studying as part of my PhD.

Solar PV

You’ve probably heard of solar PV panels and how people have saved a lot of money by installing them on their homes. A family member of mine recently got some and is now saving ~50% on energy bills during the summer! Solar panels are a passive flex-tech where they generate energy during the daytime and can help power the day-to-day demands of your house, therefore reducing the power load from the electrical grid. I use the term passive because the panels don't actively divert power usage like other technologies.

Home Heating Controls

Heat pumps are a hugely efficient way of heating your home and work best with low-temperature heating using zonal controls, but they are still quite expensive for many people. So even if you still have a gas boiler, you can use smart heating controls to control indoor air temperatures better. So when there’s cheap electricity, you could increase your temperature set-point, and when it's more expensive, you can drop the temperature a degree or two, saving lots of money whilst still being fairly comfortable at home.

Thermal Energy Storage

Thermal energy storage options are quite varied these days; traditional types like hot water tanks and new electrically driven phase-change material (PCM) are just couple of the most popular options. PCM thermal batteries can store the latent thermal energy held in materials (such as Sunamp thermal batteries). During my initial pilot project, I found that using a hot water tank to heat and store hot water at night/off-peak during the day was one of the most cost-efficient ways of being flexible because hot-water tanks are still inexpensive compared to other technologies.

Home Battery

Batteries, like the Tesla Powerwall or the Enphase IQ Battery, are expensive but can provide lots of flexibility. You can charge the battery using your excess solar or during low-price times (like the night), then use it when you need it to avoid expensive electricity periods. The charging and discharging of batteries to save money is called energy arbitrage. This is exactly how industrial-scale batteries are used to support the grid.

Electric Vehicles

Electric vehicles (EVs) are effectively home batteries on wheels. When they are plugged into your house, they can charge up and discharge to power your energy demands in the evening. Octopus Energy has a smart charging tariff for EVs called Powerloop that can earn you money by letting them manage the charging of your EV during peak times, and it will still be charged by the time you need it again!