Hydropower is an old technology which is proven to be safe and reliable. Given that it is also a renewable resource which can be used to produce electricity without the release of harmful pollutants, this technology demands a closer look.
Hydro Power DiagramHydropower systems
All watercourses naturally flow downhill. Thus upland waters have energy potential which is released as they gradually flow down to lower levels. A hydro power system is designed to capture and convert this latent energy resource into kinetic energy via a turbine. This in turn powers a generator which is then used to harvest electricity. The amount of electricity which can be generated depends on the volume of flowing water, and also the height and rate of descent. The system efficiency is also a factor which determines the ultimate electricity output.
Advantages of hydro systems
• Lower electricity bills
Once installed, a hydropower system continuously generates electricity and may well produce excess power beyond your needs.
• Feed-in Tariffs
For systems which meet the qualifying criteria, a Feed-in Tariff offers a payment for the total amount of electricity generated, plus a further payment for any electricity surplus to requirements which is ‘sold back’ and input to the grid.
• Low-cost heating and hot water
With a hydropower system, any excess electricity not required for powering appliances and lighting can be used to provide, or contribute to, hot water and heating needs.
• A low-cost alternative for remote locations
The installation of a hydropower system can be costly, but in remote locations this may still represent a cheaper option than connecting to the National Grid.
• Low-carbon option
Because a hydropower system generates no harmful emissions, it represents a green, renewable energy option.
Hydro system requirements
The viability of hydropower clearly depends upon the location. In all cases a potential hydropower site must be professionally assessed before any installation work begins.
A suitable stream or river with hydropower potential will essentially have:
• a good flow rate – which means a substantial volume of water flowing through per second
• a good head of water – which requires a reasonably short, steep fall.
Seasonal flow variations are also important and the expected flow in summer drought conditions is often the determinant factor.
Hydropower systems are often suitable projects for development by communities rather than individuals.
Financial implications (Outlay)
Hydropower system installation costs vary considerably dependant upon the location and electricity-generating potential of the site. For an average home, the cost of a typical 5 kW system, including installation, would start at around £25,000. Actual costs would be determined by the amount of site preparation required and the type of generating equipment installed.
Ongoing maintenance costs of hydropower systems tend to be modest and the life-expectancy of most systems is 40 to 50 years, or more. River flood-debris is the chief risk, and efficient screening at the intake is the usual precaution to safeguard the equipment.
Projected savings and potential income
Savings are linked to the operational effectiveness of the turbine, which is influenced in turn by the frequency of optimal generating conditions in your river or stream. Prior to installation, the site assessment should predict the likely performance expectations and estimate the electricity output.
Hydropower installations qualify for Feed-in Tariffs and thus each kWh of the total electricity generated by the system earns a payment. Similarly, any electricity which is surplus to requirements receives a further payment when exported back to the grid.
For those in remote off-grid locations, storage of surplus electricity in batteries for later use can represent a viable option. Similarly, investing in energy-efficient products and appliances maximises the benefits of the electricity generated. If you do not have a viable hydro power water source on your property, then there are other green alternatives that can save you money. Solar power in particular is a great way to generate electricity and reduce your supplier bills. The UK governments is currently offering to finance installations of solar panels under the green deal, for more information, speak to an approved green deal installer.
