Questions and Answers

• Do I need to have a fall (drop) to generate power? Yes, the power output is directly related to the quantity of water passing through your site and the fall; although on ‘free-stream’ sites you can extract some of the “kinetic energy’ like a windmill, but the turbine has to be very large for a relatively small output.

• How much power do I need? A typical house in the UK may only use the equivalent of a few kilowatts of continuous energy input, but we tend to install appliances that are designed regardless of their peak power demand. So if you design your house and appliances around the plant, 5kW can probably supply all your needs. If you have a draughty farmhouse it will need to be nearer 10 kW and a damp castle will need a lot more!

• What kind of turbine is best? Don’t worry about the turbine at this stage and don’t listen to people who haven’t ever run or maybe even seen a turbine, it’s not that simple!

• Does a mill leat/lade need to be concrete lined? No, only where the ground is very unstable or porous need you consider such expensive options.

• Is the electricity AC or DC? Almost all of my schemes produce 240 volts AC and are designed to operate in the same way that a diesel generating set would operate. DC systems are very inconvenient in that they require an expensive inverter and batteries and it is more difficult to transport the electricity more than a few yards without encountering heavy losses.

• Can I use the ‘ratty’ old alternator or motor I have in the shed? Yes, but I wouldn’t, because a really good one will pay for itself in a very short time and could be giving you ten or even fifteen percent more output.

• Can I use my old turbine or waterwheel? Yes, but it won’t be a cheaper option, and will probably be more expensive, but it may also be a more rewarding and aesthetic solution.

• Can I run a heat-pump as well? Yes, you can either run the compressor directly from the turbine shaft or electrically if the requirement for heat is remote from the turbine. The heat can be taken directly from the mill-stream as opposed to burying a considerable length of plastic pipe for the evaporator circuit.

• What is the typical efficiency of the plant? An overall efficiency figure between sixty and sixty five percent is realistic, as few small turbine can achieve efficiencies much over 80% and standard generators much over 75%.

• What will it all cost? The whole project including civil engineering will be in the range £1500 to £3000 per kW of electrical output. There is a lot of variation in the cost of the civil engineering, but you can typically expect to get a 15% return on investment.

• Are there any financing schemes? Yes, we can offer a scheme whereby you only have to cover the costs of getting planning and obtaining an EA licence and after that we can do everything. Depending of the exact details of the site, you may end up only having to donate a few pence per kWh to help Third World hydro schemes, in exchange for all the electricity you can generate.

• Can I do any of the work myself? Yes, there are lots of things that an enthusiastic site owner can do to further his scheme, even if he or she is not an engineer or builder.

• How far can I bring the electricity? A few hundred yards at 240 volts. Half a mile or so at 400 plus volts and a mile or so will require over 1000 volts to keep the cable sizes and losses reasonable (less than 10%).

• Can the cables be installed underground? Yes, and it need not be more expensive than overhead and avoids the danger of lightning strikes.

• Can I sell the power to the National Grid? Yes in theory, but there is very little if any financial benefit and an enormous mound of ‘red tape’ that will cost you far more. It is hardly worthwhile under 25 kW unless there are other advantages that you can get from load management.

• But aren’t the new feed-in tariffs very generous? Yes, to generate the power you can get almost 20 pence per unit even if you use it yourself, but you get only an additional 3 pence per unit if you sell it, and in many cases it will cost you more than you will get back.

• Can I build and install my own plant? This is the big question at the moment because DECC are trying to force anyone who installs equipment to be MCS certified at a cost of at least £3500 and to only use certified products that on a one-off basis would cost you a further £10,000 in ‘Red Tape’. I am questioning whether this is even legal under European legislation.

• Will it still generate electricity when there is a power cut? Most installations won’t, simply because the generator needs grid power to ‘excite’ and they don’t have governing systems to control the frequency, but nearly all the systems that I design and build, can run during a power cut.

• Will it run most domestic appliances without harming them? Yes, within the capacity of the particular plant, it will operate all normal equipment and safety systems are provided in case the plant is overloaded.

• Can I just produce heat? Yes technically, but there may be other options if and when the Renewable Heat Initiative (RHI) is brought in next year.

• How dangerous are hydro systems? Care should always be taken when working near water and electricity. There are particular dangers that should be addressed before installation starts, during installation and during operation. I am always happy to discuss these issues.

• Do I need planning permission to install this equipment? Existing installations or mills would probably not require planning permission, since there is an established use, but since many mills are listed buildings, any significant works would have to be put to the planners and the EA.

• Do I have to pay for the water? No, in the UK there is now no charge for power generation, after years of conflict that saw most of the remaining commercial watermills close down or switch to electricity for grinding.

• Will I have to pay rates? The question only arises if you are selling electricity as a commercial concern.

• Do I need Environment Agency/SEPA (in Scotland) Approval? Unfortunately yes, since there are some amongst us who have caused damage to rivers, and it is vital that fish and ecosystems are protected.

• Will it be an eyesore? Not if I design and build it, because I think it should be difficult for most people to even find one of my plants (I have a significant number of plants that nobody knows about, proving that they really are environmentally benign). If in doubt, they should be installed underground, or use local materials such as stone and wood.

• Will it be noisy? Low head turbines are usually very quiet, higher head plants less so. Most of the difficulty comes from the cooling fans of standard high-speed generators, which are why we change the fan design, bury or insulate the powerhouse to keep the noise in.

• Will it kill the fish? No, because if it does you will soon be closed down. Proper fish screens or ‘fish-friendly’ equipment that allows the fish to pass through unharmed are mandatory and feasible.

• What happens if the water dries up? It stops working, but if the plant has been properly surveyed and planned, you will know that before you start, and most power comes in the winter which is when we want it for heating.

• What happens if it all freezes up in winter? In cold climates it is important to design the plant so if it does freeze it will not get damaged.

• Do I need to be an engineer to run it? No, you simply need to be keen to learn a few basic things; in fact non-engineers usually have far less problems because they tend not to fiddle with things!

• Do I have to do any maintenance? If the leaf screening is automatic or semi-automatic, the maintenance is minimal. If screening is manual, it can be a nightmare during the autumn. Main services are every five to ten years and will take about a day.

• Will it be damaged by silt? Yes if it is a high head turbine, otherwise it has to be able to withstand it.

• How long will the plant last? I usually guarantee a plant to outlive the owner (or me, since I am now 60!), but I do have one of my great great grandfather’s hydraulic rams still working from 1864!

• How long will the whole process take? Installation work needs to be done in the summer and the EA in particular can take anything from six months to about ten years to make up their minds, so I would say that between one and three years is realistic.

• Can I do a short training course? Yes, I am going to restart them after a break of 30 years (I thought green energy would catch on after the first oil crisis)

• Where do I go from here? Follow the instruction in the ACTION file.