Energy bars

This is a very text-heavy post but I thought I would share our efforts to save on our energy usage in our home.

With the constantly rising costs of energy, we have always tried to use as little electricity and gas as possible in our home and installed solar systems for both electric and hot water.

In 2016 we had the roof on our home replaced and foam insulation added which has made a very big difference to the heat loss in the winter and overheating problems we had in the summer months.

We have gas-powered central heating with hot water via a cylinder and with the addition of the solar hot water system a few years ago we have been able to reduce our gas usage by around a third throughout the year. During the summer months, the solar panel heats the water cylinder to a high enough temperature for showers and so the only gas usage is for cooking.

We have experimented with various on and off-grid solar PV systems and for a few years, we tried using a pair of 125Ah 12v batteries which were charged from five 100W solar panels.  This was used for low-voltage power to run our home data logger and low-voltage lighting in several of our rooms. We also had a mains inverter which ran our home lighting circuits but we soon found that even with 500 watts of solar energy coming in, this would only run the lights for a few hours before the batteries dropped to below 11 volts and the inverter would shut off.

We removed the 12V batteries and used the solar PV panels with a 600W grid tie mains inverter which feeds a small amount of power back into the household mains when the sun shines.

Lighting Savings

Our house originally had incandescent bulbs, with 500W halogen outdoor lights in the garden. We changed to compact fluorescents (CFL bulbs) when they first became available. In the past 3 years, we have replaced all the CFLs with LED lights with similar light output and we changed to using daylight colour bulbs which we find give off a much better light compared to the more orange-coloured CFLs and "warm white" LEDs. 

Most rooms have bayonet fittings, but the kitchen and loft used 5ft (1500mm) fluorescent tubes and these were replaced with Philips LED tubes. When we first purchased the LED tubes, they cost around £50 each but they are now down below £10 each when purchased online!

Total Watts for all lighting

Original Incandescent bulbs: 2360W

Using CFL and fluorescent tubes: 1879W

Current LED Bulbs: 224W

Total Saving: 2136 W

Measuring the electric usage

A few months ago we purchased a HOPI meter after seeing one being used on the Bigclivedotcom youtube channel and we have been using this to measure the energy usage of different devices around the house. We compared the accuracy of the HOPI meter against our bench multimeter and it seems to be close enough for mains measurement.

Our home data logger also monitors and logs the electric meter and gas meter readings via pulse sensors so we can have a daily total of energy used. We have experienced some issues with missed pulses which we are currently trying to fix.


Our desktop machines and dual monitors have been optimised as much as possible with SSD drives replacing hard disks and high-efficiency power supplies. The monitors use around 50W each when running and this only drops to around 25W when on standby, so we have to remember to power them off at the UPS when not in use.

We tested the APC Uninterruptible Power Supply (UPS) and when it is powered down, they still use around 8 watts and so if they are left connected to the mains 24/7 they cost £9.81 per year (current electric price is 14p per KWh). By turning these off at the mains at the end of the working day we are saving about £10 each year on each computer.

Our network system comprises a network switch, firewall, Linux server, router and a small UPS which combined use 50 watts and costs us £62 per year. We have a small network attached storage server and this uses 65W when running and 0.4W when in standby mode so we now power this down to standby mode at night to save power.

TVs and Smart Speakers Standby savings

We measured the standby power from our TVs and smart speakers and sound bars and were surprised to find that when not being used they are drawing around 25W each on standby.

Our living room TV and the speaker use 24W, my TV and its soundbar use 26W and Andrews's TV uses 26W on standby which adds up to 675kW/h used each year at a cost of over £110.

As the TVs and sound systems are only used part of each day, we decided to install plug-in power timers in each room and only have the units powered on when they are likely to be used.  With these savings, the standby power consumption will save us around £65 per year.

The Loft Workshop

All our mains-powered test equipment in the loft has always been plugged into separate wall sockets in the past, but we wanted to be able to switch all of the kit on and off using a single switch.

The new IEC distribution board purchased at a local radio rally a few months ago allows us to have all our mains-powered test equipment connected to a single socket.

IEC power box
IEC power distribution board.

When all the equipment is connected but left on standby the internal power supplies are drawing between 25-30 watts so being able to turn it off using a single switch, when not in use, will give us a small power saving on our electric bills.

Electric and Gas meters

Our electric and gas meters are the older "dumb" style meters with pulse outputs.  We have to take the readings manually and send them to our energy providers and once or twice a year they send someone to read the meters to check we are giving them the correct numbers each time.

EON energyWe are currently using e.on energy for our electric and gas supply and for the past months they keep contacting us via letters and emails asking us to get the newer smart meters.

After the latest emails from e.on, we decided to get them to install new SMETS 2 smart meters so the readings could be sent automatically and in the future use, their own API’s to be able to access live and historic usage data.

Changing from our current "dumb" meters to new "smart meters" would mean that we would lose our current gas usage monitoring as the new smart gas meters do not have a pulse output but the smart electric meters would have the flashing front LED our datalogger uses.

Smart Meter installation and failure

We booked an appointment for the engineer to come today to install the new smart meters but after he had been working on it for nearly 2 hours with the electricity turned off he found there was a problem with the network connection and the electric meter was failing to "connect to the provisioning service".  This meant that he couldn’t proceed with the gas meter installation and would have to remove the smart electric meter and reinstall our old "dumb" meter!

The engineer told me that this happens from time to time and the network often drops out for hours at a time so they cannot install any new meters while it is offline. The smart meters use mobile networks to communicate and I know the corner of the house where the meter is installed is a radio blackspot also my mobile phone has very poor reception there so that may have been the problem.

We were told to contact our energy provider again to arrange for another engineer visit to try to install the meter again but after more research about problems with the current second-generation meters and network connectivity issues, we think we will stick with our older "dumb" meters and continue to use our own data logger to keep track of our energy usage.