Hydropower An overview Chris Elliott CEng MIMechE Chartered Mechanical Engineer Renewables First BHA Member
Who we are: • • •
Established for 10 years, recently acquired Western Renewable Energy Based in Stroud, Gloucestershire with a growing team of 15 engineering / technical staff. Clients include British Gas, GlaxoSmithKline, Sainsbury’s, Tesco, Carbon Trust, utility companies, royalty, plus a large number of private landowners and farmers.
Turnkey service providers for low, medium and high head hydropower projects. Provide all services from feasibility, licensing and design, installation and project management. Similar set of services also provided for wind projects (330 kW – 3 MW turbines, normally single turbines or small clusters). Why use Renewables First? We have a long track record and lots of satisfied customers. Also because we actually design and install systems, we know what we are doing. That practical experience feeds back into our early-stage feasibility work making it more accurate and realistic.
What is Hydropower? Dams – High impact Storage
Water Mills – Low impact! Run-of-River
What is Hydropower? Diversion
Channel
Forebay
Pipeline
Power Line
Powerhouse
Tailrace
Hydro Basics It all depends on the head
Head (H)
H
Hydro Basics …. and Flow Rate
Head (H) Flow rate (Q)
Q
H
Hydro Basics Power Water power available proportional to HxQ Power output also depends upon: •Head losses •Turbine Efficiency •Generator Efficiency •Drive losses
Q
x
H
Hydro Basics “There’s no such thing as an 80kW water turbine” Medium Head = 10m Flow = 1m³/s P = 80 kW
Low Head = 1m Flow = 10m³/s
P = 80 kW
Small water turbine Large water turbine
Hydropower in the UK Present situation • Pumped Storage • Storage hydro
• Run of river hydro • Micro hydro • Energy recovery from water supply and water treatment
Hydro in the UK • Total UK typical peak demand 50GW • UK Hydro capacity 1.5GW • Pumped Storage 3GW • Most new SW projects up to 100kW
Incentives • Feed In Tariff – 19.2p for 15 – 100kW – Around 5% degression later in 2014
Regulation - EA • Available flow leaving enough for migration • Screening – exclusion or safe passage • Fish passes for upstream migration • Eel passes • New guidelines (Apr 1st)
Regulation - Other • In England & Wales a Flood Defence Consent is also required. • Planning permission (+ Listed Building Consent) from the local authority. • Permission to grid connect the system from the Distribution Network Operator (DNO).
THE PROJECT LIFE CYCLE Five stages 1. 2. 3. 4. 5.
Pre-Feasibility Feasibility Planning and Licensing Detailed Design Construction
Indicative timescales
Feasibility study •
• • • • • • • •
Detailed site visit / survey to understand the site layout, measure levels across the site, review existing infrastructure, review options for locating the hydro system (intake, penstock pipework, turbine house, electrical connection etc.). Detailed analysis to work out the best location for the hydro system and then the head at that location is calculated from the surveyed data. Detailed flow analysis using flow records from the SEPA / EA and corrected-back to the site using LowFlows software. Calculations of power output and annual energy production. Outline of recommended turbine type and system layout. System cost estimate and summary of income from the finished system, and calculation of return on investment. Summary of expected licensing and consenting requirements. Recommended next steps to proceed with the project. Detailed report summarising all of the above.
Renewables First normal cost for feasibility studies:
< 100 kW £3,100 100 kW to 250 kW £3,600 250 kW to 500 kW £4,700
Impulse turbines • High head – 25m or more head – In SW mainly small flows – 100 l/s or less – Upland rivers – Long deprived reaches – Minor rivers – Quite hidden
Crossflow Turbines • 5 to 25m head typically • Typically 50 to 1000 l/s • Flat efficiency curve • Lots of SW sites suitable • Makes use of draft • Often good for old mills on smaller rivers
Reaction machines • Francis machines – Similar applicability to Crossflows – Available new, also common historical design – Reliable and typically from UK firm
• Kaplan machines – – – –
5m or less head 1000 l/s or more Needs screening Great efficiency
Screw turbines • • • •
5m or less head 500 l/s or more No screening needed Good efficiency
Installations
• Often significant civils, much below water level, needs specialist designers, contractors
Installations 1
Installation 2
Installation 3
Installation 4
Sources of further information:
•BHA Micro hydro guide •Environment Agency ‘Good Practice Guide’
•www.renewablesfirst.co.uk
www.british-hydro.org
HYDROPOWER
A New Lease of Life