How is EROEI calculated?
How is EROEI calculated?
EROI is calculated by dividing the energy output by the energy input. Measuring total energy output is often easy, especially in the case for an electrical output where some appropriate electricity meter can be used.
Is it better to have a high or low EROEI?
Generally, we can expect that the highest available EROI energy sources will be used first because these offer the most energy for the least effort. A net energy gain is achieved by expending less energy when attempting to acquire and use a source of energy. EROI analysis is considered part of a life-cycle analysis.
Which energy source has the highest EROEI?
Hydroelectric power generation systems have the highest mean EROI value, 84:1 (n of 17 from 12 publications), of electric power generation systems (see Lambert et al., 2012 for references) (Fig. 3).
What is the EROI of biofuels?
The net energy ratio (energy return on energy invested, or EROEI) for biofuels in general, and corn ethanol in particular, is abysmal. The EROEI of gasoline, by comparison, is between 5:1 and 30:1, depending in part on the source of the petroleum.
What is a good Eroei?
An EROI sum of at least seven is required to be considered a viable and profitable energy source, while an EROI score of seven represents a break-even point. It means that there were no net profits or no net losses for the company – it “broke even”.
What is the Eroei for solar energy?
Energy returned on energy invested
Energy returned on energy invested (known as EROI or sometimes EROEI) is the ratio of the amount of useable energy produced by a given energy source to the amount used by humans to acquire it.
Is a low EROI good?
“A very low EROI means most people have to work in the energy-supply industries. One could reduce our EROI to 2.5:1 and survive, but there would be… [fewer] possibilities for other activities.” At the same time, he conceded that “EROIs make a little more sense for a finite fossil fuel resource, like an oil field.
Why are biofuels so expensive?
Lower energy density and the price of raw materials make biofuels more expensive when producing heat. And the higher the biofuel content of the fuel, the lower the energy density and thus energy efficiency (see Fig. 1).
Why is biodiesel so expensive?
Consumers are extremely price sensitive when it comes to their gas and fuel. This raises the question of exactly why biofuels like ethanol and biodiesel are so expensive compared to the cost of crude oil that comes out of the ground. The simple answer to this has to do with Mother Nature and energy density and time.
How much does a gallon of biofuel cost?
As mentioned previously, the cost to produce biodiesel is $5.53-$6.38 per gallon. This is higher than the current price of regular diesel.
How does the tax credit for biodiesel affect imports?
In years when the tax credit was in effect during the time of production (i.e., not applied retroactively), such as in 2013 and in 2016, domestic production and foreign imports of biodiesel increased significantly relative to the preceding years.
What is the EROEI of gasoline?
The EROEI of gasoline, by comparison, is between 5:1 and 30:1, depending in part on the source of the petroleum. Additionally, in recent years the ethanol industry’s huge purchases of corn as a feedstock for fuel production have caused corn prices to increase, raising the cost of basic food items for the global poor.
What is EROEI and why is it important?
Any time it requires more energy to produce a source of energy than the energy you get out of it one should pause and consider the implications. EROEI stands for Energy Return on Energy Invested.
What is the EROEI of corn ethanol and biodiesel?
Corn Ethanol EROEI of 1.2:1 Sugar Cane Ethanol EROEI from 8.3:1 to 10.2:1 If this isn’t the craziest of all developments that have occurred in the last 20 years — ethanol and biodiesel from corn is more about subsidizing American farmers to grow far more corn than can be consumed as food within the North American market.
