permaculutre renewable energy
DESCRIPTION
pdc overview presentationTRANSCRIPT
Permaculture: Renewable
Energy
Permaculture: Renewable
EnergyKevin BayukKevin Bayuk
OverviewOverview Outline and brief description of renewable energy
technologies
General overview of technologies and applications integrated using permaculture design
Information on costs
Common barriers and issues limiting wide spread use/dissemination
Outline and brief description of renewable energy technologies
General overview of technologies and applications integrated using permaculture design
Information on costs
Common barriers and issues limiting wide spread use/dissemination
General Principles & Considerations
General Principles & Considerations
Thermodynamics EMERGY / EROEI Supply and Demand
Negawatts (Accept Feedback) Embrace Diversity Integrated Solutions Observe and Interact -
Scale
Thermodynamics EMERGY / EROEI Supply and Demand
Negawatts (Accept Feedback) Embrace Diversity Integrated Solutions Observe and Interact -
Scale
Terminology - Units of Measurement
Terminology - Units of Measurement
Ampere: Amps - A unit in which electrical current flow ismeasured.
Voltage: Volt - V unit in which electrical force is measured.
Wattage: Watts unit in which electrical power is measured and isobtained by multiplying Voltage and Ampere.
Watt Hours: Whrs is A unit in which electrical power consumption is measured and is obtained by multiplying the wattageby the number of hours of use.
ExamplesExamples
An electrical bulb burning on 220 volts draws 3 Amps. What is the Power consumption if it runs for two hours?
Power consumed will be
= watts x hours
= volts x amps x hours
= 220 x 2 x 3
= 1320 watt hours
i.e. 22000 watt hours = 22 kwh 1000
You pay for your household electricity
Kilowatt HourKilowatt Hour
as so much $
per kilowatt hour (kwh)
which is just the watt hours divided by a thousand.
Solar water heatingSolar water heating Heats your tap water not your
radiators 50% of hot water needs overall Roof should face between SE and
SW 3-4m2 array for households Need hot water tank 20-30 years useful life
Heats your tap water not your radiators
50% of hot water needs overall Roof should face between SE and
SW 3-4m2 array for households Need hot water tank 20-30 years useful life
Opportunity: Combine with re-roofing to reduce costs
Flat plate Evacuated tubeUnglazed
Increasing efficiency/cost
TypesTypes
How do they work?How do they work?Closed system Open (direct) system
Photovoltaics (PV)Photovoltaics (PV)
Convert light into electricity
Single PV Cell: 1.5 Watts
Typical Panel (30-40 cells): 40-60 Watts
Convert light into electricity
Single PV Cell: 1.5 Watts
Typical Panel (30-40 cells): 40-60 Watts
Opportunity: Captures photons at peak use periods
Polycrystalline SiThin Film
Increasing efficiency/cost
Monocrystalline Si
TypesTypes
How do they work?How do they work?
Load AnalysisLoad Analysis Household load analysis estimates the
peak and average power and energy required Mind the “Edge Events” like
refrigerator cycling on Some might be reduced or time-shifted
to decrease system costs A spreadsheet program like Excel will
speed analysis of the various loads, their use time, peak power, and energy required List the loads, enter the power, time per day,
and compute the rest From total energy required and total power,
one can compute the size of solar modules and batteries
Household load analysis estimates the peak and average power and energy required Mind the “Edge Events” like
refrigerator cycling on Some might be reduced or time-shifted
to decrease system costs A spreadsheet program like Excel will
speed analysis of the various loads, their use time, peak power, and energy required List the loads, enter the power, time per day,
and compute the rest From total energy required and total power,
one can compute the size of solar modules and batteries
Solar PotentialSolar Potential
Roof-top Solar Array Computations
Roof-top Solar Array Computations Find the south-facing roof
area; say 20 ft * 40 ft = 800 ft2
Assume 120 Wp solar modules are 26 inches by 52 inches; 9.4 ft2/120 watt; 12.78 W/ft2
Assume 90% of area can be covered, 720 ft2, ~9202 W
and that there are (e.g) 5.5 effective hours of sun/day; 51 kWh/day
The south-facing modules are tilted south to the latitude angle
76 modules would fit the area, but 44 would provide an average home with 30 kWh/day and cost ~$17600 for modules alone
Find the south-facing roof area; say 20 ft * 40 ft = 800 ft2
Assume 120 Wp solar modules are 26 inches by 52 inches; 9.4 ft2/120 watt; 12.78 W/ft2
Assume 90% of area can be covered, 720 ft2, ~9202 W
and that there are (e.g) 5.5 effective hours of sun/day; 51 kWh/day
The south-facing modules are tilted south to the latitude angle
76 modules would fit the area, but 44 would provide an average home with 30 kWh/day and cost ~$17600 for modules alone
Siemens Solar SM110
Maximum power rating, 110 W
Minimum power rating, 100 W
Rated current. 6.3 A
Rated voltage, 17.9 V
Short circuit current, 6.9 A
Open circuit voltage, 21.7 V
Battery Charge ControllerBattery Charge Controller Limits charge current to
protect battery from overheating and damage that shortens life
Disconnects battery loads if voltage falls too low (10.6 V is typical)
Removes charge current if voltage rises too high (14V is typical)
Regulates charge voltage to avoid battery water gassing
Diverts output of source to a secondary load (water heater or electric furnace) if battery is fully charged Saves energy wisely
Limits charge current to protect battery from overheating and damage that shortens life
Disconnects battery loads if voltage falls too low (10.6 V is typical)
Removes charge current if voltage rises too high (14V is typical)
Regulates charge voltage to avoid battery water gassing
Diverts output of source to a secondary load (water heater or electric furnace) if battery is fully charged Saves energy wisely
Soltek Mark IV 20 Amp
Regulator
“Big as a breadbox” for a 4 kW inverter
Storage BatteriesStorage Batteries Lead-acid (car) batteries
are most economical; but must be deep-cycle type
Critical rating is 20-hour value or Reserve Capacity (RC) in minutes at 25A load
Charge cycle is ~70% efficient -- rather wasteful
Requires maintenance to ensure long life
A home might have ten of these batteries
Need to know the length of time without full sun in days
Inverter must match series battery voltage
Lead-acid (car) batteries are most economical; but must be deep-cycle type
Critical rating is 20-hour value or Reserve Capacity (RC) in minutes at 25A load
Charge cycle is ~70% efficient -- rather wasteful
Requires maintenance to ensure long life
A home might have ten of these batteries
Need to know the length of time without full sun in days
Inverter must match series battery voltage
Soltek Deep-Cycle
BatteryAP-27
12 Vdc,115 A-hr 20-hour rate
BatteriesBatteries
So if a battery is rated at 24 Amp Hour Capacity we can draw -2 Amps from it for 12 hours or-12 Amps for two hours or-24 Amps for 1 hour etc.
The capacity of a battery can be given in watt hours
but this is very cumbersome,
and since the battery voltage is always fixedwe divide the watt hours by the voltage.
= volts x Amps x hours Volts
To get Amp hours.
InverterInverter The inverter converts low voltage (12V to 100s V) direct current to 120 Vac
Synchronous inverters may be “inter-tied” with power line to reduce billable energy
In “net metering” states, the energy is metered at the same rate going into and out of the electrical grid --- no storage required (except for outages)!
Loads can use 12 volt low-voltage directly at higher efficiency with special lamps
The inverter converts low voltage (12V to 100s V) direct current to 120 Vac
Synchronous inverters may be “inter-tied” with power line to reduce billable energy
In “net metering” states, the energy is metered at the same rate going into and out of the electrical grid --- no storage required (except for outages)!
Loads can use 12 volt low-voltage directly at higher efficiency with special lamps Trace
Legend 4 kilowatt Inverter
InvertorsInvertorsAn invertors is an electronic device that will convert D.C. Power into A.C Power i.e. 12 volt D.C. from a battery into 220 volt A.C. Smallest practical size for our application is 150 watt.One of 10 KW is large enough to power a 3 Bedroom House.
Invertors come in two basic types:
True Sine wave such as EDM Delivers
50Hz
Modified Sine Wave
50Hz
Disadvantage: Not as efficient as true sine waveEquipment such as specialized electronic medical instruments and measuring instruments might not perform, as they should.No problem with normal household and consumer electronic products.
Energy TransmissionEnergy Transmission
Solar power is expensive, so design wires for 1% loss instead of usual 3 to 5% for utility power
Use higher voltage (120Vac for long lines) instead of 12 Vdc
Spend more on larger wire than normal to reduce resistance loss
Battery and inverter wires might be AWG #0 or 2 or larger
Inverter output is 120Vac, so AWG#12 and 14 are common for 20A and 15A home service
Danger with batteries is not shock but flash burns and flying molten metal Special dc-rated fuses and circuit breakers are required
Solar power is expensive, so design wires for 1% loss instead of usual 3 to 5% for utility power
Use higher voltage (120Vac for long lines) instead of 12 Vdc
Spend more on larger wire than normal to reduce resistance loss
Battery and inverter wires might be AWG #0 or 2 or larger
Inverter output is 120Vac, so AWG#12 and 14 are common for 20A and 15A home service
Danger with batteries is not shock but flash burns and flying molten metal Special dc-rated fuses and circuit breakers are required
Some Important Electrical Information
Some Important Electrical Information P = E•I = E2/R = I2•R,
where P is power (instantaneous), E is electromotive force, I is intensity or current, and R is resistance
Energy = P•t, where t is the time that power flows V = I•R for a load or E = I•R for a source,
where V is voltage drop across resistor Wire size numbers roughly double the area and halve
the resistance for every three size number changes #18 AWG is used in ordinary lamp cord (zip cord) #18 AWG has a resistance of 6.385 ohms per 1000 ft #12 AWG has a resistance of 1.588 ohms per 1000 ft #9 AWG has a resistance of 0.7921 ohms per 1000 ft #6 AWG has a resistance of 0.3951 ohms per 1000 ft #3 AWG has a resistance of 0.197 ohms per 1000 ft
P = E•I = E2/R = I2•R,where P is power (instantaneous), E is electromotive force, I is intensity or current, and R is resistance
Energy = P•t, where t is the time that power flows V = I•R for a load or E = I•R for a source,
where V is voltage drop across resistor Wire size numbers roughly double the area and halve
the resistance for every three size number changes #18 AWG is used in ordinary lamp cord (zip cord) #18 AWG has a resistance of 6.385 ohms per 1000 ft #12 AWG has a resistance of 1.588 ohms per 1000 ft #9 AWG has a resistance of 0.7921 ohms per 1000 ft #6 AWG has a resistance of 0.3951 ohms per 1000 ft #3 AWG has a resistance of 0.197 ohms per 1000 ft
Solar Power ApplicationsSolar Power Applications
Technology type
System Application
PV (solar electric) Grid connected Supplementing mains supply
PV (solar electric) Stand-alone Small home systems for lighting, radio, TV, etc. Small commercial/community systems, including
health care, schools, etc. Telecommunications and navigation aids Water pumping Commercial systems Remote settlements Mini-grid systems
Solar thermal Connected to existing water and/or space heating system
Supplementing supply of hot water and/or space heating provided by the electricity grid or gas network
Solar thermal Stand-alone Water heating, i.e. for rural clinics Drying (often grain or other agricultural products) Cooking Distillation Cooling
PV systems: Strengths & Weaknesses
PV systems: Strengths & Weaknesses
Strengths WeaknessesTechnology is mature. It has high reliability and long lifetimes (power output warranties from PV panels now commonly for 25 years)
Performance is dependent on sunshine levels and local weather conditions
Automatic operation with very low maintenance requirements
Storage/back-up usually required due to fluctuating nature of sunshine levels/no power production at night
No fuel required (no additional costs for fuel nor delivery logistics)
High capital/initial investment costs
Modular nature of PV allows for a complete range of system sizes as application dictates
Specific training and infrastructure needs
Environmental impact low compared with conventional energy sources
Energy intensity of silicon production for PV solar cells
The solar system is an easily visible sign of a high level of responsibility, environmental awareness and commitment
Provision for collection of batteries and facilities to recycle batteries are necessary
The user is less effected by rising prices for other energy sources
Use of toxic materials is some PV panels
Wind PowerWind Power• Temperature differences create currents affected by earth’s rotation and land contours = wind
• A wind turbine obtains its power input by converting the force of the wind into a torque (turning force) acting on the rotor blades.
• The amount of energy which the wind transfers to the rotor depends on the density of the air, the rotor area, and the wind speed.
• Temperature differences create currents affected by earth’s rotation and land contours = wind
• A wind turbine obtains its power input by converting the force of the wind into a torque (turning force) acting on the rotor blades.
• The amount of energy which the wind transfers to the rotor depends on the density of the air, the rotor area, and the wind speed.
Wind TurbinesWind Turbines
Wind turbines start at 400 watts and go up to many megawatts
Only work when the wind blows Not easily installed on houses
Work better when at the top of tall towersDo not like turbulent airCan be noisy
Wind turbines start at 400 watts and go up to many megawatts
Only work when the wind blows Not easily installed on houses
Work better when at the top of tall towersDo not like turbulent airCan be noisy
Siting a TurbineSiting a Turbine
Requires** clearance without obstructions 200 yards from turbine within 20 feet of turbine height
Requires a good macro wind resource with good micro wind elements
Requires** clearance without obstructions 200 yards from turbine within 20 feet of turbine height
Requires a good macro wind resource with good micro wind elements
OrientationOrientationTurbines can be categorized into two overarching classes based on the orientation of the rotor
Vertical Axis Horizontal Axis
Turbines can be categorized into two overarching classes based on the orientation of the rotor
Vertical Axis Horizontal Axis
Performance: EnergyPerformance: Energy
•Based in kWh a month not rated power •Household sized turbine (10->23’ diameter)
Monthly kWh Production
0
100
200
300
400
500
600
700
800
900
5.6 7.0 7.9 8.9 10.0 11.2 12.3 13.4 14.5 15.6 16.8 17.9 19.0 20.2 21.2 22.4 23.5 24.6
Wind Speed Average - MPH
kWh
Tower HeightsTower HeightsAnemometors, to be accurate, need to be in the exact location for a yearTower height restrictions may apply but it is important to get the generator up as high as possible to maximize energy productionAvoid obstructions position turbine at least 30 feet above nearby features
http://rredc.nrel.gov/wind/pubs/atlas/
Wind Power ApplicationsWind Power Applications
Technology type System Application
Wind power - electrical
Grid connected Supplementing mains supply
Wind power - electrical
Stand-alone, battery charging
Small home systems Small commercial/community
systems Water pumping Telecommunications Navigation aids
Wind power - electrical
Stand-alone, autonomous diesel
Commercial systems Remote settlements Mini-grid systems
Wind power - mechanical
Water pumping Drinking water supply Irrigation pumping Sea-salt production Dewatering
Wind power - mechanical
Other Milling grain Driving other, often agricultural,
machines
Wind systems: Strengths & Weaknesses
Wind systems: Strengths & Weaknesses
Strengths Weaknesses
Technology is relatively simple and robust with lifetimes of over 15 years without major new investment
Site-specific technology (requires a suitable site)
Automatic operation with low maintenance requirements
Variable power produced therefore storage/back-up required.
No fuel required (no additional costs for fuel nor delivery logistics)
High capital / initial investment costs can impede development (especially in developing countries)
Environmental impact low compared with conventional energy sources
Potential market needs to be large enough to support expertise/equipment required for implementation
Mature, well developed, technology in developed countries
Cranage and transport access problems for installation of larger systems in remote areas
The Technology can be adapted for complete or part manufacture (e.g. the tower) in developing countries
Micro HydroMicro Hydro• water+gravity+turbine+generator = electricity
• Site dependent
• Can be most efficient renewable energy source (little environmental impact)
• Small scale
• Can cost as little as one tenth of a PV system of comparable output
• Low volume and high head systems work and high volume low head systems work
• water+gravity+turbine+generator = electricity
• Site dependent
• Can be most efficient renewable energy source (little environmental impact)
• Small scale
• Can cost as little as one tenth of a PV system of comparable output
• Low volume and high head systems work and high volume low head systems work
You need two things to make power
Head and Flow
You need two things to make power
Head and Flow
Measuring HeadMeasuring Head Pipe with
pressure gauge at the bottom (1 person)
2.31 feet = 1 psi This gauge reads
38 psi 38 psi x 2.31
feet/psi = 88 ft of head
Pipe with pressure gauge at the bottom (1 person)
2.31 feet = 1 psi This gauge reads
38 psi 38 psi x 2.31
feet/psi = 88 ft of head
5 gallon bucket5 gallon bucket
This may be tricky…
Small stream, little waterfall
Most typical method for microhydro
5 gallon bucket5 gallon bucket
If the measured flow using a 5 gallon bucket and a stop watch was 5 gallons in 1.5 seconds, how many GPM would this be?
If the measured flow using a 5 gallon bucket and a stop watch was 5 gallons in 1.5 seconds, how many GPM would this be?
GPMgal
200min1
sec60
sec5.1
5
Larger StreamsLarger Streams
Float MethodFloat Method Weir
Power EstimatePower Estimate
Power (watts) = Net Head (ft) * Flow (GPM)9-14 (use 10)
Power (watts) = Net Head (ft) * Flow (GPM)9-14 (use 10)
10 assumes a system efficiency of 53%
NozzlesNozzles
Flow through the pipe is controlled by the nozzle size
Mollies Branch Case Study
Mollies Branch Case Study
100 ft of net head Stream flow: 300 gpm Design flow: 85 gpm Penstock: 1200’ of 4” HDPE Turbine: Harris Hydro 4-
nozzle PM Power: 850 W for now Energy: .85 kW x 24 h/day
x 30 day/mon = 612 kWh/mon
Cost = about $16,000
100 ft of net head Stream flow: 300 gpm Design flow: 85 gpm Penstock: 1200’ of 4” HDPE Turbine: Harris Hydro 4-
nozzle PM Power: 850 W for now Energy: .85 kW x 24 h/day
x 30 day/mon = 612 kWh/mon
Cost = about $16,000
Measuring Flow
The 4” HDPE arrives in 50’ lengths
Fusing the pipe with the ASU Wind & Hydro Class
Fusion welder
• Shave pipe ends
• Heat with 500 degree iron
• Press ends together to fuse
• Makes a “double roll back bead”
The penstock gradually drops 100 feet along the 1200
feet of pipe. It is supported along the
bank with steel stakes and aircraft
cable
This log house is moved into place to house the turbine
The wire run and Balance of System is roughed in
A battery box is built to contain the eight Trojan L16 batteries (48V)
A silt trap/intake filter is built from a 55 gallon plastic
drum
The penstock is connected to the turbine house
A stand is constructed for the turbine.
A union and hinge allows the turbine to be tilted back for
servicing.
Screw-type gate valves insures slow operation
The water passes through the floor and returns to the
creek
Water is diverted from the creek to the silt trap
A second silt trap barrel is added to improve performance
The battery bank and inverter are wired. The electrician installs a subpanel for the hydro loads.
The log house does a nice job of reducing the sound level (sounds like a sewing machine)
Hydropower: Strengths & Weaknesses
Hydropower: Strengths & Weaknesses
Strengths Weaknesses
Technology is relatively simple and robust with lifetimes of over 30 years without major new investment
Very site-specific technology (requires a suitable site relatively close to the location where the power is needed)
Overall costs can, in many case, undercut all other alternatives
For SHP systems using small streams the maximum power is limited and cannot expand if the need grows
Automatic operation with low maintenance requirements
Droughts and changes in local water and land use can affect power output
No fuel required (no additional costs for fuel nor delivery logistics)
Although power output is generally more predictable it may fall to very low levels or even zero during the dry season
Environmental impact low compared with conventional energy sources
High capital/initial investment costs
Power is available at a fairly constant rate and at all times, subject to water resource availability
Engineering skills required may be unavailable/expensive to obtain locally
The technology can be adapted for manufacture/use in developing countries
Biomass BasicsBiomass Basics
-Biomass fuels have the potential of providing 4%-25% of the United States energy needs
-3.6% of United States Energy Consumption derived from Biomass Sources
-Biomass fuels have the potential of providing 4%-25% of the United States energy needs
-3.6% of United States Energy Consumption derived from Biomass Sources
Three major forms of biomass energy-Solid Biomass (Wood, Incineration)-Liquid Fuel (Ethanol, Biodiesel)-Gaseous Fuel (Landfills, Methane)
Solar Energy Conversion
Solar Energy Conversion
1 hectare = ~2.5 acres
Boiling 1l of WaterBoiling 1l of Water
Rocket Stoves and Mass Heaters
Rocket Stoves and Mass Heaters
Bioenergy Technologies
Bioenergy Technologies
GasificationGasification
Biomass heated with no oxygen Gasifies to mixture of CO and H2
Called “Syngas” for synthetic gas Mixes easily with oxygen Burned in turbines to generate
electricity Like natural gas
Can easily be converted to other fuels, chemicals, and valuable materials
Biomass heated with no oxygen Gasifies to mixture of CO and H2
Called “Syngas” for synthetic gas Mixes easily with oxygen Burned in turbines to generate
electricity Like natural gas
Can easily be converted to other fuels, chemicals, and valuable materials
PyrolysisPyrolysis Heat bio-material under pressure
500-1300 ºC (900-2400 ºF) 50-150 atmospheres Carefully controlled air supply
Up to 75% of biomass converted to liquid
Tested for use in engines, turbines, boilers
Currently experimental
Heat bio-material under pressure 500-1300 ºC (900-2400 ºF) 50-150 atmospheres Carefully controlled air supply
Up to 75% of biomass converted to liquid
Tested for use in engines, turbines, boilers
Currently experimental
Anaerobic DigestionAnaerobic Digestion
Decompose biomass with microorganisms Closed tanks known as anaerobic
digesters Produces methane (natural gas)
and CO2
Methane-rich biogas can be used as fuel or as a base chemical for biobased products.
Used in animal feedlots, and elsewhere
Decompose biomass with microorganisms Closed tanks known as anaerobic
digesters Produces methane (natural gas)
and CO2
Methane-rich biogas can be used as fuel or as a base chemical for biobased products.
Used in animal feedlots, and elsewhere
Methane DigestersMethane Digesters
BioFuelsBioFuels Ethanol
Created by fermentation of starches/sugars
US capacity of 1.8 billion gals/yr (2005) Active research on cellulosic
fermentation Biodiesel
Organic oils combined with alcohols Creates ethyl or methyl esters
Vegetable Oil
Ethanol Created by fermentation of
starches/sugars US capacity of 1.8 billion gals/yr (2005) Active research on cellulosic
fermentation Biodiesel
Organic oils combined with alcohols Creates ethyl or methyl esters
Vegetable Oil
Bioenergy ApplicationsBioenergy Applications
Fuel state Application
Biogas Supplementing mains supply (grid-connected)
Biogas Cooking and lighting (household-scale digesters) Motive power for small industry and electric needs
(with gas engine)
Liquid biofuel Transport fuel and mechanical power, particularly for agriculture
Heating and electricity generation Some rural cooking fuel
Solid biomass Cooking and lighting (direct combustion) Motive power for small industry and electric needs
(with electric motor)
Bioenergy: Strengths & Weaknesses
Bioenergy: Strengths & Weaknesses
Strengths Weaknesses
Conversion technologies available in a wide range of power levels at different levels of technological complexity
Production can create land use competition
Fuel production and conversion technology indigenous in developing countries
Often large areas of land are required (usually low energy density)
Production can produce more jobs that other renewable energy systems of a comparable size
Production can have high fertiliser and water requirements
Conversion can be to gaseous, liquid or solid fuel
May require complex management system to ensure constant supply of resource, which is often bulky adding complexity to handling, transport and storage
Environmental impact potentially low (overall no increase in carbon dioxide) compared with conventional energy sources
Resource production may be variable depending on local climatic/weather effects, i.e. drought.
Likely to be uneven resource production throughout the year
GeothermalGeothermal
Energy available as heat from the earth
Usually hot water or steam
High temperature resources (150°C+) for electricity generation
Low temperature resources (50-150°C) for direct heating: district heating, industrial processing
No problems of intermittency
Energy available as heat from the earth
Usually hot water or steam
High temperature resources (150°C+) for electricity generation
Low temperature resources (50-150°C) for direct heating: district heating, industrial processing
No problems of intermittency
TrompeTrompe
RE Applications: Summary
RE Applications: Summary
RE Technology Energy Service/Application
Wind – grid‑connected & stand-alone turbines, wind pumps
Supplementing mains supply. Power for low-to medium electric power needs. Occasionally mechanical power for agriculture purposes.
PV (solar electric) – grid- -connected, stand‑alone, pumps
Supplementing mains supply. Power for low electric power needs. Water pumping.
Solar thermal – grid‑connected, water heater, cookers, dryers, cooling
Supplementing mains supply. Heating water. Cooking. Drying crops.
Bio energy Supplementing mains supply. Cooking and lighting, motive power for small industry and electric needs. Transport fuel and mechanical power.
Micro and pico hydro Low-to-medium electric power needs. Process motive power for small industry.
Geothermal Grid electricity and large-scale heating.
Village-scale Mini-grids usually hybrid systems (solar-wind, solar-diesel, wind-diesel, etc.). Small-scale residential and commercial electric power needs.
CONCLUSIONSCONCLUSIONS
Renewables can be used for both electricity and heat generation. There is a wide range of renewable energy technologies suitable for implementation in developing countries for a whole variety of different applications.
Renewable energy can contribute to grid-connected generation but also has a large scope for off-grid applications and can be very suitable for remote and rural applications in developing countries.
Demand conservation is the key
Renewables can be used for both electricity and heat generation. There is a wide range of renewable energy technologies suitable for implementation in developing countries for a whole variety of different applications.
Renewable energy can contribute to grid-connected generation but also has a large scope for off-grid applications and can be very suitable for remote and rural applications in developing countries.
Demand conservation is the key