ENVS EXAM 3 - RENEWABLE ENERGY.

ENVS EXAM 3 - RENEWABLE ENERGY Which of the types of renewable energy would be best able to provide base demand for electricity? (Base demand refers to the demand that is always present for power.) - answers Hydroelectric power Which of the following is a major barrier to the increased use of solar photovoltaic (PV) energy in homes? A. solar PV doesn't work in most locations B. there are large up front costs to solar PV installation C. solar PV cells generate 220 volt electricity, which is incompatible with many US appliances D. there are no state or federal incentives that support the installation of solar panels - answers B. there are large up front costs to solar PV installation Which of the following is NOT a barrier to incorporating renewable energy technologies at a large scale in the US? A. it is difficult to store energy produced by renewable technologies B. the US has few sources of renewable energy C. society in general has not yet made implementing renewable energy options a priority D. energy infrastructure needs to be upgraded to match where energy is produced to where it is needed - answers B. the US has few sources of renewable energy If the US power grid is already fragmented, in the future when we adopt more renewable energies, what would be a problem if the three grids become completely independent, only running on the renewable energy sources in their areas? - answers Renewable energies are hard to store and are only available at certain times, regardless of the size or inter connectivity of the grid Whats the main potential benefit of second-generation biomass fuels as an energy source compared to the first? - answers Second generation biomass fuels would not require the use of food crops like corn and sugar cane __________________________ takes advantage of the relatively constant temperature of the surface of the earth to cool the house in the summer and warm it in the winter. - answers Geothermal heat pump (residential) Whats an alternative way to harvest hydro-power for a country that has already used its major rivers? - answers Micro-hydropower facilities could be installed that generate a lesser amount of electricity with low environmental impacts Gallon of gasoline = 9 kg CO2 emissions, if it takes 2 kgs of coal to produce a gallon of biomass fuel and each kg of coal = 3.75 kg CO2 emissions, how much would CO2 emissions be reduced or increased if you use a gallon of biofuel instead of gasoline? - answers decreased by 1.5 ( 2 x 3.75 = 7.5, 7.5 - 9 = 1.5) Name three drawbacks of switching from fossil fuels immediately to biomass fuels? - answers 1. mass production of some biofuels could potentially limit food supplies. 2. it requires a lot of energy to convert biomass into biofuel. 3. regular gasoline engines cannot use pure biofuels without being converted. Batteries could play an important role in helping renewable energy sources such as wind and solar contribute more to energy use. What is this role and why is it important? - answers Batteries store energy and in doing so help distribute energy from periodic renewable sources like wind and solar over a continuous period of time. ..................................................continued..................................................................