Author: lowctech

BatteryLeave a comment

Powerwall storage in practice

lowctech

The Powerwall was installed at the end of February 2022 and it pretty much works as expected. When we have a full year of figures will post about the difference it has made to our electricity bill. Until then here’s a few things we’ve learnt since it was installed. Summer operation – We turned the Powerwall into ‘Self Powered’ mode on 1st June – from then until the beginning of October we used less than 20 kWh of day rate electricity – that’s around £6 in total or 5p per day – much less than the standing charge! We used … Continue reading Powerwall storage in practice

BatteryLeave a comment

Why a Tesla Powerwall battery?

lowctech

Adding a battery to our home started to make sense when electricity prices rocketed just as our electricity consumption dramatically increased due to our heat pump. We knew the battery would let us use more of the energy generated from our solar panels and allow us to use some cheap overnight electricity during the day in winter. So far it seems to be working – year to date we have used 88% of the power generated from solar – that’s 3.56 MWh compared to 40% (1.67 MWh) for full year 2021. Don’t have full year figures yet, the battery was … Continue reading Why a Tesla Powerwall battery?

Everything elseLeave a comment

What is a kWh anyway?

lowctech

You can’t go very far into the electric future without encountering kilowatt hours (kWh) – electricity consumption, battery storage, heat output – kilowatt hours are everywhere. A kWh is a unit of energy – it can be used for any kind of energy – electrical, heat, food, exercise. Yes there’s lots of other units of energy, some current such as Joules and calories, some historic such as British Thermal Units (BTUs), some scary such as tonnes of TNT for explosions. The kWh is favoured for the electric future as it represents a useful amount of energy so we can all … Continue reading What is a kWh anyway?

Electric Vehicle, SolarLeave a comment

Solar EV charging in practice

lowctech

Here’s how we charge our EV during the summer. It takes a bit of effort to get things set up – up to you if you think it’s worth it. We do. It needs to be really easy to plug the ‘granny’ lead into the car – it’s something you are going to need to do many times. We leave the charging lead permanently plugged into a smart plug in the garage. The cable and charging connector loop over a ‘hook’ right by where the car charge socket is when parked. Walk to the front of the car, open the … Continue reading Solar EV charging in practice

Heat PumpsLeave a comment

Making your heat pump work great

lowctech

A heat pump may replace a gas or oil boiler in your property but practically everything about them is different. To deliver maximum efficiency and comfort a heat pump needs to be set up like a heat pump not a small boiler. Surely that’s obvious? Nope, our heat pump was installed to work exactly like a small boiler. It took a couple of engineer visits and a few emails to get it working sensibly. So what changed? Originally the boiler was set up to use ‘Flow Temperature Control’ with the flow temperature set to 45C. Not a good idea – … Continue reading Making your heat pump work great

SolarLeave a comment

Do you need to clean your solar panels?

lowctech

There’s lots of sites on the internet answering “Yes, you do need to clean your solar panels”. Many of these sites also offer cleaning services – perhaps a potential conflict of interest? Strangely none of these sites give numbers for the performance loss caused by dirt. There are several scientific papers investigating both surface and atmospheric dust effects on solar panels but a quick scan doesn’t show much consensus plus many of them are undertaken in dusty regions – not the UK. Other sites suggest that as long as the panels are sloping at more than 5, 10, 20 degrees … Continue reading Do you need to clean your solar panels?

Everything elseLeave a comment

Do you know about DNO Notification?

lowctech

We didn’t, but, my goodness, we do now. DNO stands for Distribution Network Operator – your DNO is the company responsible for delivering electricity to your property. They manage and maintain the wires, transformers and all the other infrastructure needed to deliver electrical power to end-users. You can find out who your DNO is here: https://www.energynetworks.org/customers/find-my-network-operator Your DNO needs to know if you are installing solar panels, a heat pump, a battery or even an EV charge point. The installer should do it but it’s your responsibility so you need to make sure. When our solar panels were installed one … Continue reading Do you know about DNO Notification?

Electric VehicleLeave a comment

EV Running Costs – what can you save?

lowctech

Everyone knows EVs cost less to run than petrol or diesel cars but it all depends on where and how you charge. Charging at home Charging at home from cheap overnight electricity is hard to beat for cost and convenience. As an example Octopus Go is a tariff for EV users only that offers 4 hours electricity for 7.5p per kWh between 00:30 and 04:30 each night. Using a 7kW home charge point means you can add about 28kWh to your EV each night – that’s enough for around 112 miles – assuming 4 miles per kWh* – of motoring … Continue reading EV Running Costs – what can you save?

Electric Vehicle, SolarLeave a comment

How best to charge an EV from Solar

lowctech

Not quite as easy as it sounds – a common theme in the electric future – but it can be done. We used solar charging from Apr – Sept this year, it provided 82% of all the charge put into the car and gave us more than 2,500 miles of free motoring (if you ignore the capital costs of solar and battery). As all that electricity came from the sun it was genuinely CO2 emission free – unlike charging from the grid. Read on for how. You could just plug in the ‘granny lead’ to a 13A socket but that … Continue reading How best to charge an EV from Solar

Heat PumpsLeave a comment

Heat Pump Running Costs

lowctech

Heat pumps use electricity to make low temperature heat energy from the air or ground into useful higher temperature energy that can heat your home. How do they compare with other types of home heating for running costs? The graph shows the cost in pence to provide 1 kWh of heat into your home for different types of heating: electric, gas, oil, air source heat pump and ground source heat pump. Pretty obvious electric heating is not a great choice. The graph is based on average price cap unit (kWh) figures from Oct 22 – that’s 34p for electricity, 10p … Continue reading Heat Pump Running Costs