Course lecture of MHP

1.  Necessity of Micro Hydro Power
 Power From Water
 Typical Layout
 Isolated /Mini Grid Or Grid Connected Scheme
 Micro Hydro Design Approach
 Status of Micro Hydro Power Development in Nepal and Agencies Involved
.
Microhydrobasics and status in Nepal (2 hours)

2.  The term hydro-power is usually restricted to the generation of shaft
power from falling water. [K.E.  M.E.]
 The power is then used for direct mechanical purposes (Ghatta) or,
more frequently, for generating electricity.
 Other sources of water power are waves and tides.
HYDRO-POWER

4.  Small in scale
Renewable source of energy
 Minimum environmental impact
 Site specific: you must have the resources
 Affordable
 Consistent: Produces continuously, 24*7
Micro-hydro

5. Why micro-hydro?
It has several advantages over wind, wave and solar power, namely:
 a high efficiency (70 - 90 per cent), by far the best of all the technologies
 a high capacity factor, i.e. time generating power throughout the year;
(typically greater than 50 per cent compared with 10 per cent for solar and 30
per cent for wind)
 a high level of predictability, varying with annual rainfall patterns
 a slow rate of change; the output power varies only gradually from day to day
(not from minute to minute)
 it is a long-lasting and robust technology; systems can readily be engineered
to last for 50 years or more
 it is environmentally benign; micro-hydro is in most cases ‘run-of-river’; in
other words, any dam or barrage is quite small, usually just a weir, and little or
no water is stored

7. Power from water
Equation may be rewritten as
E = ρ x V x g x h [(kg/m3) x (m3) x (m/s2) x m]
= 1000 x V x g x h [kg x (m/s2) x m]
= 1000 x V x g x h [N x m]
= 1000 x V x g x h [J]

8. Power from water
The corresponding power may be calculated as
P = E/t [J/s] = E/t [W]
= 1000 x V x g x h/t [W]
= 1000 x (V/t) x g x h [W]
= Q x g x h [kW]
Pinput = 10* Q*h [kW]

9. Pout = 𝜂 𝑐𝑖𝑣𝑖𝑙 ∗ 𝜂 𝑝𝑒𝑛𝑠𝑡𝑜𝑐𝑘 ∗ 𝜂𝑡𝑢𝑟𝑏𝑖𝑛𝑒 ∗ 𝜂 𝑔𝑒𝑛𝑒𝑟𝑎𝑡𝑜𝑟 ∗ 𝜂𝑡𝑟𝑎𝑛𝑠𝑓𝑜𝑟𝑚𝑒𝑟 ∗ 𝜂𝑙𝑖𝑛𝑒 ∗ 𝑃𝑖𝑛
= 0.95*0.9*0.8*0.85*0.96*0.9*Pin
= 0.5*Pin
= 5*Q*h KW if, Q is in m/s and h in m.
= 5*Q*h W if, Q is in lps and h in m.

10. A Typical Micro Hydro Layout(1)

11. A Typical Micro Hydro Layout(2)

12. COMPONENTS OF MICRO-HYDRO POWER PLANT

13. WEIR AND INTAKE
WEIR
 Obstruction in the river to raise the water level to divert water to headrace.
 Require neither a high dam nor a big reservoir.
INTAKE
 Structure to take water from the river.

14. Settling Basin
 A pond to collect and flush out sediments like sand and soil
 To prevent for suspended materials to enter the waterway
 Sometimes omitted in cases that inflowing sand and soil is minimal

15. headrace
 Conveys water from the intake to the forebay
 Usually an open canal made of concrete, but sometimes it is made of soil
and/or pipes

16. Forebay
 A pond-like structure at the top of the penstock to take water in the penstock
from waterway
 A spillway is connected to a forebay.
 Functions as a final settling basin for suspended materials in water

17. PENSTOCK
 Pipe to convey water from forebay to turbine.
 Steel pipe in case of high pressure.
 Hard vinyl chloride plastic pipes or FRP(Fiber Reinforced Plastic) pipes in case of
low pressure

18. POWER HOUSE
 A house for electro-mechanical equipment (turbine, generator, controllers and
panels)
 Sufficient space for dismantling equipment during repair and maintenance activities

19. TURBINE AND GENERATOR
Turbine
 Converts the water energy to rotational power
Generator
 Generates electricity from the rotational power of the turbine

20. Micro Hydro Design Approach
 CAPABILITY AND DEMAND SURVEY
 To explore what demand is there for a new scheme,
 how much and where it is needed and in what form,
 whether there is willingness and ability(capability) to pay
 HYDROLOGY AND SITE SURVEY
 This establishes the hydropower potential of the site.
 It shows how the water flow varies throughout the year,
 where must be taken for the cheapest and most effective scheme.
 It shows how much power will be available and when it will be available.
 PRE-FEASIBILITY SURVEY
 Quick cost study of a range of design options and rural energy source from
both view consumer as well as funder.
 Must compare result of energy demand survey with the hydrology study
i.e. supply demand matching.
 Recommendation for management structure, tariff structure etc. and
time-scale for institution-building and management skills

21.  FEASIBILITY SURVEY
 Detailed engineering calculation and coasting
 Golden Rule “O+M first, economics and plant factor second, engineering Design
last”
 Set out in detail about the tariff structure and how it will be implemented
 Obligation and priority rights are determined.
Micro Hydro Design Approach
Why Golden Rule??
 Because success of the scheme depends in the end on correct operational
procedures and effective management of the scheme when operating.
 To tailor the technical design to suit the level of operational and organizational
resources (skills, finance, accessibility, repair workshop techniques and tools) in the
region.
 To tailor the technical design to meet local economic conditions, such as the
financial resources of the users, how much they can afford to pay for the hydro
installation and how much time they can devote to managing it in future years
given their priorities.

22. Load factor and Plant factor
 Load Factor:
 The ratio of total energy consumed in a particular period to the total energy capacity connected
to the consumers during the same period.
𝐿𝐹 =
𝑡𝑜𝑡𝑎𝑙 𝑒𝑛𝑒𝑟𝑔𝑦 𝑐𝑜𝑛𝑠𝑢𝑚𝑒𝑑 𝑖𝑛 𝑡𝑖𝑚𝑒 𝑇
𝑡𝑜𝑡𝑎𝑙 𝑙𝑜𝑎𝑑 𝑐𝑜𝑛𝑛𝑒𝑐𝑡𝑒𝑑 𝑖𝑛 𝑡𝑖𝑚𝑒 𝑇
 The load factor considers consumer behavior pattern and the average consumption of power by
the households
 Plant Factor:
The ratio total energy consumed in a particular period to the maximum energy available from
the plant in the same period.
𝑃𝐹 =
𝑡𝑜𝑡𝑎𝑙 𝑒𝑛𝑒𝑟𝑔𝑦 𝑐𝑜𝑛𝑠𝑢𝑚𝑒𝑑 𝑖𝑛 𝑡𝑖𝑚𝑒 𝑇
𝑚𝑎𝑥𝑖𝑚𝑢𝑚 𝑒𝑛𝑒𝑟𝑔𝑦 𝑎𝑣𝑎𝑖𝑙𝑎𝑏𝑙𝑒 𝑓𝑟𝑜𝑚 𝑡ℎ𝑒 𝑝𝑙𝑎𝑛𝑡 𝑖𝑛 𝑡𝑖𝑚𝑒 𝑇
 Plant factor shows to what extent the energy available from the plant has been used.

23. Example (Load factor and Plant factor)
If 5 KW of power is used for six hours a day
from a 10 KW plant, calculate the load factor
and the plant factor?

24. Importance of Plant factor
The plant factor shows the extent of energy use
from the available energy potential.
A lower plant factor means less energy
consumption, less revenue generated and a longer
payback periods which may even increase the
plant cost. A plant factor of 0.4 in the initial years
and 0.6 or more in the subsequent years is
desirable. Plant factor can be improved by
matching power supply and demand through a
careful capability and demand survey.

25. Numerical
Tutorial 1.2

26. Micro-hydro Schemes

27. Micro Hydro status in Nepal
• Till 2008/09, 1977 micro and pico hydro plant
with total installed capacity of 13.9 MW
• By the same time, there were 6253 number of
units for mechanical power generation for
milling

28. Organizations involved in Microhydro
 Annapurna Area Conservation Project (ACAP) and Canadian Center for
International Studies are the most prominent among the number of
NGOs and INGOs in the micro hydro sector.
 Rural Energy Development Programme (REDP) of the United Nations
Development Programme provides significant assistance to the
program in addition to the AEPC's micro hydro support program. It
supports community projects in 25 districts.
 Involvement of local government (VDC's and DDC's) in energy
planning and social mobilization.
 REDP receives subsidy from AEPC on micro hydro projects.
 The Nepal Government Remote Area Development committee (RADC),
another key player, supports community owned plants with an aim of
achieving regionally balanced growth, efforts are directed at remote
areas.

29. Factors helping growth of micro-hydro
 External Technical Assistance,
 Indigenous Innovation And Conducive Government Policies
 Government Subsidy For The Last Two Decades, Initially From The Agricultural
Development Bank Of Nepal (ADB/N) And More Recently From The Alternative
Energy Promotion Center (AEPC) Interim Rural Energy Fund (IREF)

30. References
 Adam Harvey, “Micro-hydro design manual”
 Tri Ratna Bajracharya, “Mini and Micro
Hydropower System Design”
 Tokyo Electric Power Co. (TEPCO)
 khullabs.com