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Sun seekers

Jun 2017 Energy Efficiency, General, Solar power | Comments Off on Sun seekers
Sun seekers

John Forster, product manager at Heatrae Sadia, explains the gap in the market where electrical installers could be helping homeowners to make the most of solar PVs

Despite amendments to the feed-in-tariff (FiT) last year, there is still plenty of power left in solar. However, these changes do mean that it’s more important than ever for homeowners to harness the full potential of their solar PV arrays, and this presents a lucrative opportunity for savvy contractors.

Since 2002, global solar energy capacity has expanded by 5,700%, reaching 227GW. The International Energy Agency has estimated it will reach more than 400GW of installed capacity by 2020, but according to experts, this is already falling behind the real-time growth of solar.

There are many reasons for this surge in uptake, not least the ongoing education of the public around energy efficiency issues, resulting in a greater awareness of the repercussions of their day-to-day usage. As a result, consumers are increasingly looking for ways to reduce their carbon footprint, while also cutting down on their utility bills – and, for many, it seems that the answer is solar power.

PV potential

According to a number of studies, 80% of the UK public are supportive of solar power, with recent consumer research revealing that 60% who have yet to install solar panels would consider going solar by 2020.

A further incentive for homeowners, and evidence of solar’s popularity, is demonstrated by a survey conducted by Barclays bank that suggested homebuyers would be willing to pay £2,000 extra for a home that has solar panels installed.

Despite fears around changes to the original FiT payment scheme, and the consequent reduction in payments, it seems that there is still a strong interest in solar. According to TrustMark, the Government-endorsed scheme for tradespeople, consumer enquiries for solar panel installations didn’t fall in 2016, but actually rose by an astonishing 130% over the year.

However, regardless of whether solar continues to make headway this year, there are still opportunities for electrical installers given the number of households that already have solar PV capability. Currently, 904,089 UK homes feature solar PV panels, 45,000 of which are in Scotland, but many of these are using only half of the total energy produced by their panels.

The issue is that most homes are vacant during the day, which means that energy produced by the panels during sunlight hours is not used and is instead exported back to the grid. This is far less cost-effective than using the energy within the home, because the money homeowners receive through the FiT is much less than what would likely be required to buy electricity from their provider.

Storing excess power

To combat this, specially designed hot water storage cylinders optimised for use with PV arrays are now available. Here, any power that is generated in addition to the household’s normal requirements will be diverted to the cylinder, rather than being sent to the grid. The water is heated to the desired temperature and controlled by a thermostat, ready for the household to use when required. Providing the cylinder has high-quality, high-performance insulation, the water will remain hot for hours.

Only excess power is diverted to the cylinder – so normal household power requirements are not affected. Increasing electricity usage to more than the solar PV panels generate will obviously raise electricity bills rather than reduce them, so to avoid any draw from the grid, a ‘buffer’ of energy needs to be retained. Typically, if there is 2.2kW of export energy, a controller will divert 2kW into the cylinder’s immersion heater, leaving a 100W buffer.

In a property with a PV array generating a 2kW surplus and a 200-litre PV cylinder, after five hours the hot water temperature can potentially increase from 20°C to 60°C. The weather will, of course, affect the amount of energy produced, but PV cells don’t need direct sunlight to work – they can still generate some electricity on cloudy days, so even then the water will still be pre-heated, reducing the amount of energy required to heat the cylinder.

Recent research by the Hot Water Association suggested that savings of up to £130 per year can be made on electricity bills by switching from a standard electric hot water cylinder to one of these cylinders, while savings of up to £95 per year can be achieved by those using a traditional gas-fired boiler. With the latter, the Solar PV input negates the need for the boiler to switch on, or if it needs to it will be for only for a few minutes.

Solar PV cylinders do not affect FiT payments either. Where an export meter isn’t fitted (which is usually the case if the solar PV system is less than 30kWp), a ‘deemed’ usage contract will be in place – this means an export tariff is paid whether the energy is consumed or not.

Heatrae Sadia’s Megaflo Eco Solar PV Ready is specifically designed to harness excess electricity generated by domestic solar PV arrays. It’s simple for homeowners to monitor and wirelessly control the hot water system. The control unit – the Megaflo Buddy – provides a continuous record of power use and savings.

A new revenue stream

The Megaflo Eco Solar PV Ready is also simple to install. There’s no need for roof work, so there’s no scaffolding or working at height involved and, as long as the contractor has a G3 certificate, there is no requirement for any additional qualifications or training. The cylinder is pre-wired and just needs to be connected to a fuse spur.

With more than 39% of homeowners willing to spend more than £1,000 on improvements to make their home more energy efficient, it is clear that there is an appetite for products that can make the most of renewable resources. Therefore, for electrical contractors looking to capitalise on the climate of energy-consciousness, recommending a solution that can boost the efficiency of existing solar PVs is a great way of demonstrating expertise to customers and creating a lucrative new revenue stream.