solar panels
bottom menu border

Guest Post: Getting the Most out of Your Solar PV System

So you've already had you solar panels fitted or you are considering solar but wondering how you can get the most out of your investment. There are two factors to consider; firstly you should be using the free electricity that your panels are generating and secondly you should be using less electricity at night time when panels are not generating energy.

Whether you buy solar panels and earn the 25 years of FIT income and generate your own electricity or get free solar panels and forfeit the income you will still want to make the most of that free electricity. If you invest in solar you also get the benefit of getting paid for any electricity that you do not use, this is called the export tariff. This rate is currently around 3p per kilowatt exported. As the rate you buy in electricity is around 13p per kilowatt it makes financial sense to use the electricity that you generate rather than paying for it. With free solar you don't get paid for the electricity that you do not use in the home so it is doubly important you use as much of it as possible.

Monitoring your energy usage

Most people have no idea what appliances use the most energy in the home, common high drain items include kettles, toasters, ovens, irons, electric heaters, dishwashers, washing machines and tumble dryers. These are also devices you can use during peak times that your solar panels are producing energy.

How do you monitor energy usage and energy generation?

You may have heard about energy monitors that allow you to see how much energy you are using in the home. Whilst these are good they don't tell you how much energy an individual appliance is using or how much energy your solar panels are using.

monitor how much your panels are generating and how much you are using in the home

You can buy a solar pv energy monitor which will show you how much energy your panels are generating and how much electricity you are using in the home. Devices such as the Wattson will even let you know when you are using more power than your panels are supplying and vice versa. This is useful to take the guess work out of knowing when you can run the tumble dryer to use your free electricity.

A home solar energy monitor will show you how much power your panels are generating in real time, and depending on the model, show you how much power is being used in the home. This type of device, once set up, will act as a visual display to show you total energy usage and power generated by your panels.

A plug in energy monitor is a device that you can use to see how much electricity individual electrical items use in the home. Do you know how much power your computer or television uses when on standby? Want to know what the power hungry devices in your home are and identify what things you shouldn't be leaving on?

To use a plug in monitor you just unplug your appliance, place the plug into the monitor and then plug the monitor into the wall socket. It will then measure the amount of energy it uses when switched on, in standby mode and even when switched off.

Using surplus solar power to heat your water

In some countries they have net metering systems that essentially credit you for the energy you generate, but don't use and feed back to the grid. You can then draw on these credits at a later date when your panels are not generating enough energy to power your home. In the UK this is unlikely to happen but some ingenious electrical engineers are developing ways to use your surplus solar power to heat your hot water.

These solar pv immersion heaters use the electrical power from your panels to run your electrical immersion heater. There are several models that have different levels of operation. The basic principal is that when the device detects that your solar panels are generating a surplus of electricity that power is used to heat up the water in your immersion tank.

A number of systems that have been tested in real homes have shown that over the summer months most of the hot water requirements can be met by solar. The benefit of this is that you are reducing your gas bills as your gas boiler needs to do less work to supply your hot water.

Why not use less energy to start with?

Many people tend to focus on the big things rather than making simple changes at home. One little change you can do will reduce your electricity bills and works particularly well for people with solar. Replacing your halogen bulbs in your kitchen or wherever you have recessed halogen lighting with their LED equivalent can save a lot of energy and therefore lower your bills.

LED lighting reduces energy use when solar is not generating

Lighting tends to be used at night when solar panels do not generate power so using less power from the grid will help reduce your bills. Replacing a single 50 watt halogen bulb with a 4 watt LED equivalent will not only save you 46 watts per bulb but produce a brighter whiter more natural source of lighting in your kitchen. LED bulbs also produce much less heat and need replacing much less frequently, in fact LED's typically last for 50,000 hours. Many homes have multiple recessed halogen bulbs fitted and so could be saving a significant amount.

If you had six 50 watt halogens in your kitchen and typically had the lights on for 2 hours a day that would use just under 110 kilowatts of electricity over the course of a year. Compare this to using LED equivalent bulbs you would only have used a little under 9 kilowatts over that same year.

Written by Allan Burns, creator of Free Solar Panels UK a resource on renewable technologies and energy saving for the home.