44 HPM 0816

HPM-08-AUG-2016

44 RENEWA B L E E N E R G I E S Getting renewables firing on all cylinders Martyn Bridges, of Worcester, Bosch Group, discusses the often forgotten opportunity installing a hot water cylinder can present in order to maximise energy usage and efficiency It is widely accepted that, in general, renewable technology is in a hiatus. There is not a great deal of demand for domestic solar power at present. Indeed, the latest Heating and Hotwater Industry Council figures on the subject reveal that sales of solar thermal panels in April 2016 were 32% lower than they were last year, and, to date, sales for the technology this year are 35% lower than they were in 2015. At an installation level, this means only 1,159m2 of solar panels have been fitted nationwide during the first four months of the year. Given that each individual installation equates to approximately four m2, around 300 solar thermal installations have taken place this year. This is, frankly, a piffling amount and certainly a disappointment when we take into account the potential the technology holds. Has the sun set on solar? The popularity and market share of renewables, and in particular solar, has been contracting over the last five or six years. It is likely that this is due in part to the fact that solar photovoltaic (PV) always offered an appealing return on investment and a relatively short payback period as a result of the very generous tariffs initially on offer. Originally, households installing PV panels could hope to achieve up to a 43p per kWh dividend for the energy generated by the PV system. However, this incentive has not been sustainable and, as many installers will be aware, if homeowners fit PV technology today it is more likely that they will be offered closer to four pence for every kWh. If we look specifically at solar, these tariffs distorted the market, meaning that many homeowners looking to add value to, or improve the efficiency of their property were less attracted to the benefits of solar thermal, and instead, moved towards solar PV due to the perceived gains. As a result, solar thermal was almost forgotten. We must also consider that in the UK heating market there is a high proliferation of combi boilers. New builds are often designed with the combi boiler in mind, which makes accommodating renewables of any form more difficult due to the space constraints. Equally, with gas and oil proving relatively inexpensive as a fuel in the current climate, the idea of installing a totally new and unfamiliar (albeit environmentally friendly) system is understandably unappealing. While solar power is seemingly struggling for the fourth or fifth consecutive year, there is the urgent need for installers to continue to consider the technology, either in the homes of those who have already committed to solar PV technology, or as a consideration for an efficient means of boosting a property’s green credentials. Solar technology, both PV and thermal, offer a great opportunity when installed as part of a property’s heating and hot water system. A solar PV system, for example, can generate around 4kWh for the average house when it is fitted with the normal 16 panel array. This 4kw of solar PV electrical energy can be used for any number of things – not least the heating and storage of hot water when installed alongside a cylinder. The dilemma many users face in having solar PV is that while they are not in a property, and it is a sunny day, the panels are producing energy which the property will not be using. While this energy can be sold back to the National Grid, the export rate is relatively small. What’s more, in the evening – when the demand for electricity is greater – the solar PV system cannot generate energy and so homeowners are obligated to buy electricity back off the grid at approximately 17p per kWh. There are systems available which help to store the electrical power created in, what are effectively, huge battery packs. However, these are presently, roughly the same size as an American-style fridge and very expensive. While the cost – and size – of such technology will undoubtedly reduce, it should be considered that hot water cylinders have the ability to put to good use this “excess” electricity in a different way. There are numerous, relatively inexpensive, ways that a cylinder can be connected in order to redirect the output of the solar PV panels to heat water for a property. Actually using this “free” energy, as opposed to selling it back, provides a much cheaper way of maximising the energy already being generated while a property’s occupants are at work or the demand for power is low. By redirecting the electricity to power an immersion heater in a hot water system, the electrical power is converted into hot water and stored – a concept which is hard to achieve for the raw, electrical energy itself. Using solar energy like this means that while homeowners are out of the house, they are still heating the cylinder up and selling the minimal amount of energy back. By avoiding having to heat up their water once the sun has set via a boiler or immersion heater and energy bought from the National Grid, households can fully benefit from the difference between the tariffs and the cost of electricity. A cleaner, greener planet In using a product which, when connected to a solar PV system, can divert the electricity to the immersion heater in instances when no other power is being used, homeowners are able to have the best of both worlds, while helping to create a cleaner, greener planet. The combination of saving energy, and therefore, money, while boosting environmental credentials should not be ignored, and installers should feel confident in recommending such a system. www.hpmmag.com August 2016 enquiry number 131 Solar PV can be used for the heating and storage of hot water when fitted alongside a cylinder


HPM-08-AUG-2016
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