Once Caplor Energy have installed your new Solar system. you will start seeing the savings straight away. If you can change how you use energy to match the generation then you could save even more.
Different technologies require different behaviour changes to make the most of the generated energy. By being aware of your system’s output by using monitoring devices, such as the SMA SunnyBeam, will allow you to make choices as to when to use energy.
Steps that you can take to reduce the amount of electricity that you export in order of ease are:
- Use electrical appliances during the day while your PV system is working, rather than at night – for example washing machines and dishwashers (easy)
- Use the excess electricity generated to generate heat
- Use the excess electricity generated to generate hot water
- Store the electricity generated in batteries
USE ELECTRICAL APPLIANCES DURING THE DAY (EASY)
You can adjust your behaviour so that you use appliances with a high energy demand such as washing machines, dishwashers, irons and hoovers during the day when your PV system is generating more electricity. At the same time you can charge up devices such as laptops and mobile phones which run on batteries. What you are aiming for is to match the output of your PV system with your electrical consumption in real time.
If you are not at home during the day to take advantage of the surplus electricity being generated, you can buy electrical appliances with a timer delay which will enable your appliances to start working during the day while you are out.
USE THE EXCESS ELECTRICITY GENERATED TO GENERATE HEAT (MEDIUM)
You might also consider using any excess electricity to top up the likes of electric storage heaters. If you do this you have to be particularly careful not to use more electricity than would otherwise be exported if you currently buy your electricity on Economy 7 or 10. This is because any additional electricity consumed during the day will cost you more than electricity consumed during the cheaper rates available at night using Economy 7 or 10 – making you worse off.
USE THE EXCESS ELECTRICITY GENERATED TO GENERATE HOT WATER (MEDIUM)
One way of using excess daytime electricity in a more controlled way is to use it to generate hot water via an immersion heater. In order to be able to do this you will need:
- a standard hot water cylinder with an immersion heater fitted
- a PV system ideally rated at 2kWp or more
- the PV system and immersion heater connected to the same consumer unit
- an immersion relay to reduce the electrical consumption of your immersion heater from the usual 3kW to 1kW (alternatively to replace the existing 3kW immersion heater with a 1kW heater). If the electrical consumption of your immersion heater is not reduced in this way, there is a significant risk that you have to buy in electricity to make up the shortfall – costing you more rather than saving you money. But if your immersion heater is currently used to provide all your hot water (even if only at some times of the year), down-rating its output in this way is unlikely to be useful as you may find you have insufficient hot water for your daily needs.
- a current sensing relay unit to detect how much electricity is being generated by your inverter and to switch over to the immersion heater at a set point – usually 1kW. This is done on the assumption that no more than 1kW is being consumed within the home and that any excess would normally be exported to the grid.
The advice in the UK is that hot water stored in a cylinder should be kept above, or periodically rise to, above 60°C to avoid the danger of Legionella bacteria. If your down-rated immersion heater cannot do this, you will need to ensure that your boiler comes on from time to time to provide this top-up heat.
If you normally use gas to heat your hot water you will need to consider carefully whether it is more cost-effective for you to use the surplus electricity generated in this way – even taking account of the fact that your immersion heater will be more efficient than your boiler, the payback time is likely to be twice as long as for other fuels.
STORE THE ELECTRICITY GENERATED IN BATTERIES (HARD)
Excess electricity generated by your PV system can be stored in batteries even if your system is grid connected. However, good quality batteries are expensive and will need replacing every 5 to 10 years depending on the amount they are used and the depth to which they are discharged.
Installing batteries is unlikely to save you money, although you might still consider installing batteries as a backup if you live in an area which experiences frequent power cuts. There are systems (sold as system backups or power routers) on the market that can automatically switch over to battery power in the event of a power cut.
Solar Hot Water
As the energy captured from a solar hot water panel is stored in your hot water cylinder, the best way to use as much of the energy as possible is to avoid heating your hot water until the solar thermal has a had chance to put as much heat as possible into the cylinder before using any auxiliary heating. Your Caplor Energy installer will set up the system for you.
Try and have showers and baths towards the end of the day, after the tank has been heated by the sun
Don’t use power showers as these heat their own hot water with electricity, thus bypassing the hot water in a solar heated tank.
Turn off your boiler completely in the summer, You shouldn’t need to use your boiler at all during the summer months with a well designed solar hot water system. Making sure your boiler is off will ensure that even if the water temperature drops a little the boiler won’t kick in.
Fit low flow taps and shower heads. This will make sure that you are using less hot water so the solar input will go much further.