PV Gap

Alfred Said:

Energy Sources Pro's And Con's?

We Answered:

Biomass:
Pro:. Comes from a renewable source.
Con: Can not be scaled up to a level to provide the world with energy.
Hydropower:
Pro: Renewable resource. Clean
Con:. Environmentalist don't like it and will sue to stop any new Hydro projects. Most of the best sites have already been developed.
Geothermal:
Pro: Clean. Will last a long time.
Con: Environmentalist don't like it because most of the good geothermal sites are in parks, like Yellowstone national park. They will sue to stop geothermal production in those areas. Very limited number of areas that can support geothermal. The geothermal environment is hard on equipment so operating cost are high.
Wind:
Pro: Clean
Con: Environmentalist don't like it because the look ugly and kill birds and bats. They don't work when the wind is to weak or to strong. Current wind farms in Europe have a history of only producing energy about 20% of the time. Because of the unpredicatablility of wind a normal coal/oil/nuclear plant has to be on hot standby (which means it is still burning some fuel) ready to come on line when the wind dies. Very expensive. Dangerous. One failure recently sent a blade flying over half a mile away. Lucky it landed in a field.
Solar:
Pro: Clean.
Con: Environmentalist have opposed large solar farms and have sued to stop there construction. They only work in the day and there is no good way to store large amounts of electricity for the night. Expensive.
Petroleum:
Pro: Relatively inexpensive. Infrastructure already exist for it's use. Very good energy to volume ratio. Easy to transport. Relatively safe.
Con: Environmentalist don't like it. Limited supply on earth. Probably only 200-300 years worth left. A lot of it comes from countries with unpopular governments. It's takes special equipment so that it burns clean and only produces CO2 after combustion.
Natural gas:
Pro: Burns clean with very little special equipment.
Con: Environmentalist don't like it and will sue to stop new natural gas production. Hard to store and can be dangerous if it leaks.
Coal:
Pro: There is a lot of it left. 700 years worth is the current estimate. Cheap. Very safe. If it spills you just pick it up. Easy to transport. The US has an ample supply and doesn't need to import it.
Cons: Environmentalist don't like it. It requires special equipment to keep the pollution levels down. The US & Europe us them now so it is clean to burn. Places like China don't. Mining can be destructive to the land.
Uranium:
Pro: Very clean to use. Enormous energy to volume ratio
Con: Environmentalist don't like it.Waste product is very dangerous to handle. Accidents can be dangerous but not likely to happen in a well run plant.
Propane;
Pro: Burns relatively cleanly
Con: Environmentalist don't like it.Can be dangerous if it leaks. Not as clean as natural gas. Energy to volume ration lower than natural gas.

You should also think about waste to energy plants.
Pro: They burn trash. We have to get rid of it some how so why not energy.
Con: environmentalist don't like it but then they don't like anything and want everybody to live in caves with not fire.

Miriam Said:

Energy Sources Pro's and Con's?

We Answered:

Biomass
+Renewable
+Can be used on small scales in local communities as well as large plants (methane extaction)
+simple biomass is cheap so can be used with very low income groups, and in developing countries as fuel (eg stoves powered on dried excriment....use your imagination there, sick, but it works for the poorest, ethenol from crops)
+can be found everywhere
+can come in different forms (methane, dried animal excriment, bio diesel from ethenol from crops etc)
+ biofuel can be used in cars, and is already being done in brazil or mexico i believe, with western countries following suite
- to harvest in large quantaties will be very time consuming for things like methane
- crops for ethanol may be seen as wasted on fuel rather than food, a concern where famine is a problem
- it still releases carbon
- in third world countries, access to large plants requires alot of money
- small plants or individual use in third world countries, especially handling faeces poses a potential health hazard, as they are unlikely to be able to afford protective equipment
Hydropower (dams)
+renewable
+0 emissons
+can produce large amounts of electricity
+as there is almost always no problem of lack of water running through, there the dams power output is not dependant on everchanging scenarios (like drop in wind etc)
+ extra income/ recreational use can be provided by the resovoir behind the dam, for activities such as boating etc
- flood land required to make resovoir. - may displace homes and grazing areas etc for people
-expensive to build
-may cause problems downstream, for example lack of water downstream etc
- environmental issues such as denying the ability for fish to swim upstream and spawn
- very large, and takes time to build
Geothermal
+0 emissions, uses earths natural heat energy
+i dont think its that expensive compared to dams or nuclear
+cheap operating costs passes savings onto consumer with cheaper electricity (other renewable sources may be expensive to cover costs of development, and non renewable costs may increase with decreasing availiblity of fuels)
+they can be small in size but provide sufficient enough energy to sustain communities
pipes run underground to heat source, so on the surface, the size of the plant is reduced.
- is only really useful in areas with volcanic activity eg iceland
-the tectonics and geography of an area may change, making the plant useless in the future
-tapping into volcanic areas may release volcanic gasses containing sulphur into the atomshpere
-hot water needs to be dispersed in the area after electricity has been generated. may cause problems in dealing with where to dispose of it
-it is usually said to be less efficient than coal powered plants due to lower input of steam temperature and pressure
wind
+renewable
+0 emissions
+can be placed on land and offshore
+is suitable for almost anywhere in the world
+can also be used for individual power generation at home
- eyesore to some
- may hit birds during flight, killing off bird populations
- may need to cover large areas to get significant power output
-may be too expensive for developing countries still
- power output varies on winds availible
solar
+renewable
+can be used for individuals at home
+can be placed in strategic areas like deserts to get vast amounts of consistant power
+doesnt emit any steam, noise, smoke etc like nuclear/geothermal plants, wind turbines and fossil fuel plants respectively.
+ self managing to a large extent....less moving parts mean theres less to go wrong like turbines, and people dont need to be involved with the energy transformation, like coal plants (chemical to heat and then electrical energy)
-may need to have a large space to get suitable power output
-can only be consistant in power in places with high amounts of sunshine
-stops working at night
-expensive to cover large areas
-too expensive to a large extent for developing countries
petrol, gas, coal (inc propane)
+large amounts of energy
+easy to burn
+can be used as it is (petrol and gas) to power household appliances like ovens etc or vehicles
+portable in its raw form (gas is, when it is contained)
+cheap to mine or obtain
- gives off great amounts of pollution
-coal being the worst offender
-coal also emits soot which can cover houses etc in soot (yes its true!)
- emits other harmful chemicals into the air, and lead to acid rain
- unsustainible....we suspect we may run out of petrol in 20 years now, coal and gas to follow aswell
-mining for all 3 damage the environment
-can lead to environmental hazards like oil spills or gas leaks
-coal mining is quite dangerous
nuclear
+pretty sustainable (low amounts of raw radioactive material can produce verrry large amounts of energy)
+produces immense energy from a single plant
+zero emissions (thats steam coming from the plants, nothing else)
+will use less space than most renewable and
-when it goes wrong, it can lead to large areas of radiation and damage to people and wildlife. (look up chernobyl)
-expensive
-needs to be near water to run turbines, so may be an issue for space
-may be used for a couple of decades, but to take down may take alot longer due to radiation cleanup
-radiactive waste is a bi product

Wilma Said:

Can anyone help me answer an environmental science question?

We Answered:

Pros:
It is renewable.
It does not pollute.
It is a great energy source for space missions, because it is highly efficient and available in space. Therefore, it can be used to power space crafts' life support and communication systems.
The energy is free, so home-based systems can pay for themselves in short order; then save their owners big bucks over the years.

Cons:
It is highly inefficient on Earth, due to our atmosphere's deflection of much of light's invisible spectrum.
It is not always available everywhere, due to nightfall, cloudy weather, and the tilt of Earth's axis causing less direct solar radiation as you move progressively further from the equator.
Solar heating panels and photovoltaic cells are very expensive.
The process by which silica (primary active substance in photovoltaic cells) is extracted from sand uses tremendous amounts of fossil fuels.

Kathryn Said:

Stick with water, or go with Solar?

We Answered:

plant 10 trees every year no big deal its easy..
do what you can do to make a difference..
recycle
dont litter
well plant more trees ..smoke more weed
and save water drink more beer..its easy it will make a difference
i mean how hard is it ppl like to ***** about a freaking tree..
well stand up speak out talk to your congress key word LEGALIZE its simple and easy grow more hemp to make paper cloth clothing etc.. grow more hemp cut less trees.. cut less trees cleaner air less health problems..
grow more weed less crime less sicker ppl better than any meds out there its a thought...
RIGHT

roll one peace