SunampPV FAQ's

SunampPV Heat Batteries - FAQ's

Below are some frequently asked questions regarding Sunamp's SunampPV Heat Battery. If you have any questions not covered below, please contact us.

Phase Change Material;

Q. What is phase change material (PCM)?

A. Phase Change Materials (PCM) are substances that absorb and release thermal energy during the process of melting and freezing. When a PCM freezes, it releases a large amount of energy in the form of latent heat at a relatively constant temperature.

Q. What are the advantages of the Sunamp PCM in energy storage?

A. Typically the biggest loads we have are for heating, so it makes economic sense to time-shift from when energy is available to when it is needed and optimise self-consumption of on-site renewable energy.

Q. How is this different from Electrical Batteries?

A. Electrical batteries don’t store heat, they typically contain lead or lithium Ion and store electricity which must then be converted into heat. A small electrical battery and larger heat battery combination is a good combination for energy storage within the home.

Q. What kind of energy and cost savings can I expect?

A. It depends on the type of fuel being replaced and how much of your solar generation you can divert and use. Data from our trial site in Somerset, illustrated that SunampPV increased own use of generation by >30% to provide about 70% of annual hot water for the home.

Controls;

Q. Do I need a controller and what should I buy?

A. You need a device that will divert energy from your Solar PV to your heat battery; there are a lot of devices on the market that will do this and we have tested some of them and would be happy to share the results.

Space;

Q. We changed our system boiler and got rid of the tank and the old airing cupboard has been used for storage. / We don’t have the space for a tank.

A. SunampPV uses phase change materials to store energy and this is four times more energy dense than a domestic hot water tank of similar capacity. Because of this the SunampPV can be fitted into very small locations – alternative locations might include under kitchen sink or garage. These are typically areas which are also close to the combi boiler and thus provide a short pipe run and quicker heat up times.

Compatibility;

Q. My combi can’t take pre-heated hot water.

A. This is true of some older types and for these we can provide a solar valve. This allows hot water to bypass the combi and go directly to the hot taps. When the water temperature drops the valve allows this colder water to go to the combi for heating and then to the hot taps. Many new combi boilers can accept high temperature inputs; Some are listed at http://www.centralheating.co.uk/combi-preheat– if you are not sure do please ask us.

Installation and maintenance;

Q. What is the installation process and how long does it take?

A. Sunamp use approved installers. If solar has not yet been installed, the storage can be installed as part of the Solar PV system. An installation of SunampPV and controller typically takes half a day to install.

Q. What kind of maintenance is required?

A. Sunamp heat batteries have a very long life. To maintain the battery in its peak performance we recommend that you have an annual check to ensure that filters are clear and electrolytic scale inhibitors are functioning so that the heat battery performs as expected.

Q. What if I need to drain down the water system?

A. If this is necessary ask your Plumber to switch off the SunampPV first. Once the system has been refilled, turn on the hot tap to run water through the SunampPV and whilst its running turn the SunampPV power back on. This will help to get rid of any air in the pump.

Warrantee;

Q. How long will it last and what is the warranty?

A. Accelerated life cycle testing has shown us that there is almost no capacity degradation in over 14,000 accelerated cycles. This means that a 20-year operation without significant performance degradation is possible. Because of this exceptional performance, Sunamp are happy to provide the core energy storage (the Heat Batteries) with a ten-year warranty, with a two-year warranty provided on all other components not manufactured by Sunamp.

Power cut or boiler break down;

Q. What happens during a power cut?

A. During an electrical power cut, SunampPV will still heat the water until the heat battery is exhausted.

Q. What happens if my combi boiler breaks down?

A. If your heating system fails, you will still be able to get hot water. Your diversion controller also has an override or boost function; this can be used to help keep the SunampPV topped up if needed.

Health and safety;

Q. What about Legionella issues?

A. There is no Legionella issue because SunampPV does not store hot water and just like a combi boiler, water is only heated on demand.

Q. Is Phase Change Material safe?

A. The phase change material is made from Sodium Acetate which is also used in food flavouring. It is fully contained, non-toxic, non-flammable and fully safety tested. At end of life it can be recycled or used as a road or runway de-icer. Sunamp use recyclable plastics, aluminium, copper and brass.

Off Gas Grid;

Q. I’m off gas grid and don’t have a combi boiler.

A. Sunamp products can still save money by helping you to maximise your generation into heat batteries to give you heating and or hot water later when you need it.

Off Grid;

Q. I live off grid how can Sunamp products help me?

A. Living off grid can be a challenge at times when there is no sun or wind. SunampPV heat batteries are twice as energy dense as an electrical battery and cost less. It’s an automatic solution for hot water and heating, so you won’t have to waste as much time collecting, cutting and drying wood and saving it for the winter when there is less sunlight.

Different fuels;

Q. I have an oil / LPG combi.

A. Sunamp products are still able to help in each of these cases and as the fuel costs of oil and LPG are higher, then your savings will be greater.

Q. I am all electric and have no PV system.

A. Sunamp products still have a role to play and save you money!

Time shifting the heating and hot water to off peak tariffs like economy 7 or economy 10, will give you a significantly lower price, while still providing heat and hot water on demand.

It’s also worth noting that SunampPV's certified heat loss rate is ½ to ¼ better than the best hot water tanks, saving you up to 700 kWh per year.

Q. What about heat pumps, anaerobic digestion (AD) and micro-CHP systems? (Combined Heat and Power)

A. In each case Sunamp products can help optimise a renewable heat source whilst still delivering hot water and space heating on demand.

Efficiency;

Q. What are the standing heat losses?

A. The SunampPV has a loss rate of 0.579 kWh/24h that is just 24 watts.

Q. How long does it take to charge up?

A. It depends where the electricity is coming from. Off-peak for SunampPV would be quickest at under 2 hours. (5kW storage/2.8kW heating element = 1.78 hours) if from a PV system then it will depend on the excess generation over the base load being diverted to the SunampPV.

Q. How long does it take to discharge?

A. This will be subject to pipe pressure and flow rate. SunampPV operates between 1.5 and 4.5 Bar with a flow rate of up to 14 litres a minute.

Q. How much energy does it use in standby?

A. The SunampPV controller uses just 0.71 watts.

Q. Can I charge the heat battery from a heat source?

A. Yes you can, systems can be supplied with a plate heat exchanger. We commonly do this with heat pumps and bio-mass boilers. Please contact us to discuss your requirements.

Temperature;

Q. Why do I need a thermostatic mixing valve? / Can I alter the temperature output?

A. We supply a thermostatic mixing valve with the SunampPV that’s adjusted at the time of installation. Everyone has a different tolerance to hot water, so it’s good to be able to control it to your comfort level but not so hot it burns.

SunampPV does not heat the water until it is needed, (it’s not a hot tank) it’s on demand just like your Combi Boiler. The PCM delivers hot water at a relatively constant temperature of 58˚C with latent heat until its exhausted.

58˚C water might just be too hot for you. So adjusting the mixing valve to your comfort level by adding cold water to the 58˚C in the thermostatic mixing valve, extends the volume delivered at your comfort level from the SunampPV making the stored energy last longer.

Cost;

Q. What is the cost?

A. Sunamp products are sold through approved installers. If your preferred installer is not Sunamp approved, please contact us to arrange training or for details of your nearest Sunamp approved installer.

Special systems;

Q. Can I have a bespoke product?

A. Sunamp encapsulate materials into cells, and it is possible for us to create batteries which fit into awkward spaces. We are happy to provide quotes for fully customised systems.