Renewable Energy is one of the most read about and discussed topics in the world however various misconceptions remain about the advantages and disadvantages of renewable energy.Note Renewable Energy is a a very large topic and encompasses many different alternative energy forms which have their own distinct pros and cons.A Better Way to understand and explain Renewable Energy would be to look at each different forms of Clean Energy like Solar,Wind,Nuclear,Hydro,Tidal,Biomass and Geothermal Energy.Renewable Energy itself compared to Fossil Fuel forms of Non-Renewable Energy has substantial advantages and some disadvantages as well the biggest of which is Cost.Also note Fossil Fuel Energy has got a massive established base,industry and lobby.The power of the Oil,Coal and Gas Industry is strong enough without the disadvantages of Renewable Energy like intermittency (solar,wind),high costs (solar),low potential (tidal energy),catastrophic risk (Nuclear,Hydro) making it more difficult to substitute these Global Warming Energy Sources.Here is a detailed look at different Renewable Energy Sources with their Pros and Cons.

Biomass Energy Pros

1) Carbon Neutral- Note Biomass Energy results in no new net GHG emissions as it is part of the carbon cycle.Unlike coal and others forms of fossil fuel which have been buried millions of years ago and burning them adds to carbon in the atmosphere,responsible biomass energy generation results in no new carbon emissions or pollution

2) Use of Waste - Biomass Energy is an Efficient Process which results in the use of mostly animal and crop waster which would be converted into carbon dioxide anyway.To use to as energy before the conversion is an important use of the millions of tons of waste that is generated by human activities

3) Continuous Source of Power – Biomass Energy can be generated almost 24×7  unlike other forms of renewable energy like wind and solar that are intermittent in nature

4) Large variety of Feedstock – Biomass Energy can use a large variety of feedstock such as wood pellets,rice husk,bagasse etc.

5) Low Capital Investment - The capital investment required for biomass based power plants is relatively less at $1-2/watt of biomass capacity.Note wind energy is slightly higher while solar is even higher.Biomass Energy has similar capex characteristics as  other forms of conventional energy like coal,gas,oil etc.

6) Distributed Nature – Biomass plants can be built in remote areas and used as a distributed form of power generation

7) Can be built on small scale - Biomass plants can be built in 1 Mw sizes unlike other types of power which require much larges scale.For example nuclear energy requires a typical plants size of at least 500 MW to make it economical

8 0  Reduces Methane which is a major GHG gas – Decomposition of organic matter releases methane. Capturing this methane yields energy while protecting the atmosphere.The animal industry and landfills produce significant amounts of methane.

9) Easy Availability – Biomass is readily available in almost all parts of the world except the desert areas where finding biomass is difficult

10) Low Cost Resource – Biomass Energy can be produced cheaply if there is a good availability of feedstock

Biomass Energy Cons

1) Pollution in case of Poor Technology – Biomass Energy can lead to air pollution in the form of char if the biomass is not completely combusted.This happens in the case of biomass energy being produced in rural areas through bad technology

2) Feedstock Problems – One of the biggest drawbacks of biomass energy is the problem of feedstock.The plants are forced to run at lower utilization leading to higher costs if feedstock is not available due to some reason like a drought

3) Good Management Required – The operations of a biomass plant requires very good management otherwise it may run into losses or even in some cases have to shut down.It requires a skill of high order to run the plant optimally and make use of alternative feedstock in case the regular one is not available

4) Limited Potential - Biomass Energy has smaller potential than compared to other forms of energy like solar,hydro etc.

5) Controversial NIMBY - Large Biomass Plants like the one in Scotland have run into massive protests as people think it might lead to air pollution and health hazards if constructed near their homes.

Nuclear Energy Pros

1. Reliability - Nuclear Power is a highly reliable form of energy almost as good as other fossil fuel energy forms like coal,gas etc.Nuclear Power Plants except in drastic situations continue to run reliably for the whole day without any changes.
2. Low Fuel Cost - Large amounts of Nuclear Energy can be produced from the fission on radioactive elements like uranium.The costs of nuclear fuel is relatively  very low compared to other energy sources like coal and gas.Also uranium prices currently are quite low making the nuclear electricity price even lower
3. Low Electricity Cost – The Electricity produced from Nuclear Power is quite low at around 3-5c/Kwh making it very attractive to construct hydro plants.Nuclear  Plants also  have long lives of between 40-60 years which means that they are extremely profitable once constructed within reasonable costs
4. No Greenhouse Gas Emissions/Air Pollution – Nuclear electricity does not produce any GHG emissions or cause air pollution from the combustion of fossil fuels unlike coal,oil or gas.This makes them very attractive as a source of cheap,non carbon dioxide producing electricity.
5. High Load Factor - Nuclear Power Plants have very high load factors in excess of 80%.They can generate power almost 24/7 and only require shutdown for periodic maintanance
6. Huge  Potential –Nuclear Energy Potential is almost infinite compared to the limited and peak features of other forms of  energy like Wind,Geothermal,Oil,Gas and others.Only Solar Energy can be said to have more potential.Note new technologies and fuels like fast breeder and thorium are still in the works which can increase the potential of Nuclear Power more

Hydro Power Pros

1. No Fuel Cost - Hydro Energy does not require any fuel like most other sources of energy.This is a huge advantage over other fossil fuels whose costs are increasing at a drastic  rate every year.Electricity prices are increasingly rapidly in most parts of  the world much faster than general inflation.Price shocks due to high fuel costs are a big risk with fossil fuel energy these days
2. Low Operating Costs and little Maintenance - Operating labor cost is also usually low, as plants are automated and have few personnel on site during normal operation.
3. Low Electricity Cost – The Electricity produced from Hydro Power is quite low making it very attractive to construct hydro plants.The payback period is estimated to be between 5-8 years for a normal hydro power plant.Hydro Plants also  have long lives of between 50-100 years which means that they are extremely profitable
4. No Greenhouse Gas Emissions/Air Pollution – Hydroelectricity does not produce any GHG emissions or cause air pollution from the combustion of fossil fuels unlike coal,oil or gas.This makes them very attractive as a source of cheap,non carbon dioxide producing electricity.
5. Energy Storage – Pumped Hydro Storage is possible with most of the hydro power plants.This makes them ideal storage for wind and solar power which are intermittent in nature.Hydro Dams can be modified at low costs to allow pumped storage.
6. Small Size Possible - Hydroelectricity can be produced in almost any size from 1 MW to 10000 MW which makes it very versatile.Small Hydro Plants are being encouraged by government as they cause less ecological affects than large hydro plants.Even micro hydro plants are possible
7. Reliability - Hydro Power is much more reliable than wind and solar power though less than coal and nuclear as a baseload source of power.Hydroelectricity is more or less predictable much in advance though it can decrease in summer months when the water is low in the catchment areas.
8. High Load Factor - The Load Factor for Solar and Wind Energy ranges from 15-40% which is quite low compared to Fossil Fuel Energy.Hydroelectricity on the other hand  has a load factor of almost 40-60% .
9. Long Life - Hydro Plants  has a very long life of around 50- 100 years which is much longer than that of even Nuclear Power Plants.The long life implies that the lifecycle cost of a Hydel Power Plant becomes very low in the long term

Hydro Power Cons

1) Environmental, Dislocation and Tribal Rights - Large Dam construction especially in populated areas leads to massive Tribal Displacement,Loss of Livelihood and Religious Infringement as potentially sacred Land is occupied by the Government.

2) Wildlife and Fishes get Affected - The Fishes are the most affected species from Dam Construction as the normal flow of the river is completely changed form its river character to a lake one.Submergence of land also leads to ecological destruction of the habitat of land based wildlife.

3) Earthquake Vulnerability – Large Dam Construction has been linked to increased propensity of Earthquakes.Massive Earthquakes in China and Uttarakhand in India were linked to the building of Massive Dams in these countries

4) Siltation When water flows it has the ability to transport particles heavier than itself downstream. This has a negative effect on dams and subsequently their power stations, particularly those on rivers or within catchment areas with high siltation

5) Tail Risk,Dam Failure - Because large conventional dammed-hydro facilities hold back large volumes of water, a failure due to poor construction, terrorism, or other cause can be catastrophic to downriver settlements and infrastructure. Dam failures have been some of the largest man-made disasters in history.The Banqiao Dam failure in Southern China directly resulted in the deaths of 26,000 people, and another 145,000 from epidemics.

6) Cannot be Built Anywhere - This disadvantage of Hdyro Energy is present with other forms of Energy as well.Some forms of Energy are just better suited to some places.For example you can’t build a nuclear plant on top of an earthquake prone region,you can’t build a wind farm near the Dead Sea etc.Hydro Energy can only be built in particular places though enough of those places exist globally

7) Long Gestation Time - The time to construct a large hydro power project can take between 5-10 years which leads to time and cost overruns.

Nuclear Energy Cons

1. Nuclear and Radiation Accidents - This is the biggest con for Nuclear Energy and has been repeated 3 times in the last 30 years in Japan,Russia and USA.The fear of a repeat is so great that despite all the safety arrangements touted by the nuclear equipment operators and suppliers,Nuclear Energy faces an uncertain future
2. Nuclear Waste Disposal – Again a massive problem as the spent Nuclear Rods of Nuclear Reactors are prohibitively costly and difficult to dispose of.Spent nuclear fuel is initially very highly radioactive and so must be handled with great care and forethought.There is no foolproof way to dispose nuclear waste fuel after it is used in the Nuclear Reactors.The area around Nuclear Waste Sites can be dangerous to humans for hundreds of year as complex nuclear elements have half lives running into many years.the United States had accumulated more than 50,000 metric tons of spent nuclear fuel from nuclear reactors.Permanent storage underground in U.S. had been proposed at the Yucca but that project has now been effectively cancelled.Presently, waste is mainly stored at individual reactor sites and there are over 430 locations around the world where radioactive material continues to accumulate.
3. Low level of Radioactivity from Normal Operations - The nuclear industry also produces a large volume of low-level radioactive waste in the form of contaminated items like clothing, hand tools, water purifier resins, and (upon decommissioning) the materials of which the reactor itself is built
4. Nuclear proliferation – Many countries have used the ruse of nuclear energy programs to generate fuel for developing nuclear weapons.Currently there is a major international controversy with regards to the Iranian Nuclear Energy Program.Nuclear Reactors are targets for rogue state actors who can steal the fuel for creating radiation weapons
5. High Capital Investment,Cost Overruns and Long Gestation Time - The time to construct a large Nuclear power project can take between 5-10 years which leads to time and cost overruns.The Nuclear Plant being built in Finland has been one of the biggest failures in Project Finance.The reactor has been delayed by many year and has led to a massive cost overrun.Areva the main nuclear equipment supplier has endured huge losses.In fact the safety regulations and the long time of construction has brought the Nuclear Energy in the Developed World to almost a halt.
6. Regulations – The Regulations for Nuclear Energy Power Plants are many and cumbersome due to the massive risks of a failure of a nuclear reactor.This greatly increases the costs of generating nuclear power.It also leads to a long time in the actual start to the completion of a Nuclear Plant .
7. Fuel Danger - Uranium which is the main fuel used in Nuclear Fission Power Plants is limited to a few countries and suppliers.Its use and transport is regulated by international treaties and groups.India which came under sanctions because of testing of nuclear weapons had to shut many of its nuclear plants because of embargoes.

Geothermal Power Pros

1) Environment Friendly, and Global Warming Mitigation Effects – Geothermal Energy does not lead to any major mining activity,does not lead to significant GHG emissions,does not lead to health hazards like thermal power

2) No Fuel Cost - Geothermal Energy does not require any fuel like most other sources of energy.This is a huge advantage over other fossil fuels whose costs are increasing at a drastic  rate every year.Electricity prices are increasingly rapidly in most parts of  the world much faster than general inflation.Price shocks due to high fuel costs are a big risk with fossil fuel energy these days

3) Predictable,24/7 Power -Geothermal Energy is very predictable and producers power 24 hours a day,7 days as week.Other forms of Renewable Energy like Solar and Wind Energy are intermittent in nature.The electricity supply is much more uniform and reliable.

4) High Load Factor - The Load Factor for Solar and Wind Energy ranges from 15-40% which is quite low compared to Fossil Fuel Energy.Geothermal Energy has a load factor of almost 80% which is equal to that of Thermal Power and comparable to Nuclear Power.

5) No Pollution and Deaths- Geothermal Energy does not lead to pollution disasters like the BP Oil Spill and Coal Deaths which are directly related to Dirty Energy Production.

Geothermal Power Cons

1) Long Gestation Time Leading to Cost Overruns – The Gestation Time for permitting,financing,drilling etc. can easily take 5-7 years to develop a geothermal energy field.Compare this to 6 months for a small wind farm or 3 months for a Solar PV plant

2) Slow Technology Improvement – Geothermal Energy has the potential to generate 100s of gigawatts of electricity through new techniques like EGS.However the technology improvement has been slow with setbacks.

3) Financing is the biggest problem in developing projects particularly for small project developers in this industry.There are few big geothermal developers like Chevron and Calpine.

4) Regulations – Drilling for new geothermal energy fields,buying of geothermal companies in foreign geographies faces innumerable hurdles.Magma which is one of the biggest geothermal energy companies faced massive local opposition in trying to buy an Icelandic company.This prevents the growth of pureplay geothermal companies in acquiring a critical scale.

5) Limited Locations – Geothermal Energy can only be built in places which have the geological characteristics favorable to generation of geothermal power.Note there have been talk that Enhanced Geothermal Energy (EGS) can lead to a massive increase in the number of locations which can generate Geothermal Energy,however EGS is facing environmental issues.

Solar Power Pros

1) Environment Friendly – Solar Energy does not lead to any major mining activity,does not lead to significant GHG emissions,does not lead to health hazards like thermal power

2) Declining Costs - Solar Costs are declining at a rapid pace and are rapidly approaching grid parity in most parts of the world.The use of semiconductor techniques ensures that the costs should continue to decline in the future as well

3)No Fuel and Low Maintainance - Solar Energy does not require any fuel like Wind Energy and the Operation and Maintainance Costs are extremely low.This is a huge advantage in these days when gas and oil disruptions are causing energy insecurity.Libya,Russia are all examples

4) No Pollution and Deaths- Solar Energy does not lead to pollution disasters like the BP Oil Spill and Coal Deaths which are directly related to Dirty Energy Productionl.

5) Almost Unlimited Potential – Solar Energy Potential is almost infinite compared to the limited and peak features of other forms of  energy like Wind,Geothermal,Oil,Gas and others.Only Nuclear Energy has potential similar to Solar Energy

6) Size Advantages - Solar Installations can be installed in various sizes with as little as 200 Watts and as big as a 1000 MW.This is not possible for other energy forms which require a minimum large size such as Coal,Nuclear etc.

7) Quick Installation - Solar Energy can be installed very quickly.Small residential installations can be installed in as low as 3 days.This is much faster compared to other  energy sources

Solar Power Cons

1) Higher Costs that Fossil Energy Forms – This is the biggest disadvantage cited by anti-Solar Power activists despite the massive decline in costs that Solar Power has seen over the last  decades.It has been estimated that solar power costs fall by 20% for every 100% increase in supply.The Solar Cost Curve has declined massively in the last 2 years as cheap Chinese solar production has made solar panel costs come down by  50% .Note in the next 4-5 years expect an average decline of around 10% per year which would make solar energy competitive with fossil fuel energy in most parts of the world.Current solar power costs between 15-30c/Kwh depending on the solar radiation of the particular location,type of technology used etc.

2) Intermittent Nature - One of the biggest problems of Solar Power ( Solar PV that is ) is that it is intermittent in nature as it generates energy only when the sun shines.This problem can be solved with energy storage however this leads to additional costs.This argument also does not make sense for a US DOE study indicated that solar and wind intermittent power won’t be a problem till 30-40% of the electricity in the US is from these 2 forms of renewable  energy.Smart Grids and Cheaper Energy Storage in the future should allow even higher penetrations of Wind and Solar Power possible.

3) High Capital Investment – A Solar Plant can cost around $3.5-6 million to be spent in building 1 Megawatt.This is said to be too high,however this again is one of the silliest arguments.The costs of energy can only be compared by Levelized Cost of Energy (LCOE) which calculates the cost of energy over the lifetime calculating the capex,fuel costs,maintenance,security and insurance costs.While it is true that the initial capital investment for solar power is quite high,the lifecycle cost of solar energy is not that high.

4) Cannot be Built Anywhere - This disadvantage of Solar Energy is present with other forms of Energy as well.Some forms of Energy are just better suited to some places.For example you can’t build a nuclear plant on top of an earthquake prone region,you can’t build a wind farm near the Dead Sea etc

Wind Energy Pros

1) No Pollution and Global Warming Effects – Wind Turbines does not lead to pollution which is one of the biggest advantages of Wind Energy.Note there are costs associated with the equipment used to build and transport Wind Equipment but the running of Wind Energy leads to no pollution

2) Low Costs – The Costs of Wind Energy has reached the level of Gas powered Energy and can be generated at extremely low rates of around 7-8c/KwH in favorable conditions

3) Big Industrial Base - Wind Energy has become a mainstream source of energy and a large industrial base already exists .This allows a rapid deployment of Wind Power in most places in the world.The number of Wind Turbine Producers is increasing with a number of Asian firms entering the industry.

4) No Fuel Cost - Wind Energy does not require any fuel like most other sources of renewable energy.This is a huge advantage over other fossil fuels whose costs are increasing at a drastic  rate every year.Electricity prices are increasingly rapidly in most parts of  the world much faster than general inflation.Price shocks due to high fuel costs are a big risk with fossil fuel energy these days

5) Offshore Advantage – The next big growth spurt in Wind Energy is coming from the offshore Wind Energy sector.Huge Wind Turbines of 5 MW and above are being built around 30-40 kms from the coasts.This has the advantage of no land usage,no noise problems and the wind is much better leading to higher load factors.The costs are currently higher but in the future are expected to come rapidly come down.USA has enough offshore wind potential to replace the whole fossil fuel electricity being consumed right now

6) Small Wind Turbines gaining some traction – While Wind Turbines are not generally used in distributed form,it is possible to now use small wind turbines being built by a number of companies to power small establishments.

Wind Energy Cons

1) Low Persistent Noise - There have been a large number of complaints about the persistent level of low level nosie from the whirring of the blades of a wind turbine.There have been cases reported about animals on farms getting affected by wind turbine noise.

2) Loss of Scenery - The sight of giant 200 metres tall towers has drawn objections from neighbours about wind power leading to loss of scenery and beauty.The Cape Wind Energy project off the shore of Massachusetts has been delayed by over 10 years as it has drawn serious objections from the owners of coastal homes about loss in their property values

3) Land usage - Wind Turbines can sometimes use large amounts of land if not properly planned and built.The construction of roads to access the wind farms etc also takes up some land.

4) Intermittent Nature - Wind Power is intermittent in nature as it generates energy only when the wind blows.This problem can be solved with energy storage however this leads to additional costs.

Tidal Power Pros

1. Renewable,non-Polluting and Carbon Negative - Tidal Energy is completely renewable,does not lead to any pollution of the air and does not lead to any carbon emissions like Fossil Fuels
2. Predictable - Tidal Wave Energy is very predictable as the Tides rise with great uniformity.Other forms of Renewable Energy like Solar and Wind Energy are intermittent in nature.The electricity supply is much more uniform and reliable in case of Tidal Power
3. No Fuel - Tidal Power needs Water for Generation of Electricity in its catchment area.It does not need fuel like Thermal,Gas or Oil Powered Power Stations
4. Low Costs – Once a Tidal Energy Power Plant starts running,its costs are extremely low.The biggest Power Plant in France run by EDF works at 1.5c/Kwh which is lower than either nuclear or coal energy which are the cheapest forms of power
5. Long Life - A Tidal Barrage has a very long life of around 100 years which is much longer than that of even Nuclear Power Plants.The long life implies that the lifecycle cost of a Tidal Energy Power Plant becomes very low in the long term
6. High Energy Density - The Energy Density of Tidal Energy is much higher than that of other forms of Renwable Energy like Wind Power
7. High Load Factor - The Load Factor for Solar and Wind Energy ranges from 15-40% which is quite low compared to Fossil Fuel Energy.Tidal Energy has a load factor of almost 80% which is equal to that of Thermal Power.

Tidal Power Cons

1. High Initial Capital Investment - Tidal Barrages require massive investment to construct a Barrage or Dam across a river estuary.This is comparable to construction of a massive dam for Hydro Power.This is perhaps the biggest disadvantage of this technology
2. Limited Locations – The US DOE estimates that there are only about 40 locations in the world capable of supporting Tidal Barrages.This is because this Tidal Energy Technology requires sizable Tides for the Power Plant to be built.The limited number of locations is a big hurdle.
3. Effect on Marine Life - The operation of commercial Tidal Power Stations has known to moderately affect the marine life around the Power Plant.It leads to disruption in movement and growth of fishes and other marine life.Can also lead to increase in silt.Turbines can also kill fish passing through it.
4. Immature Technology – Except for Tidal Barrage,the other forms of Technology generating Tidal or Wave Power are quite immature,costly and unproven
5. Long Gestation Time – The cost and time overruns can be huge for Tidal Power Plants leading to their cancellation just like that of the Severn Barrage in the UK.Many of the Tidal Power Stations like the gigantic Plant being planned in Russia will never come to fruition because of the very long gestation time.
6. Difficulty in Transmission of Tidal Electricity – Some forms of Tidal Power generate power quite far away from the consumption of electricity.Transportation of Tidal Energy can be quite combersome and expensive.
7. Weather Effects – Severe Weather like Storms and Typhoons can be quite devastating on the Tidal Power Equipment especially those place on the Sea Floor.