But suddenly, the COVID-19 pandemic brought trade, travel, và consumer spending lớn a near-standstill. With billions of people recently under stay-at-home orders and economic activity plunging worldwide, the demand for và price of oil have fallen further và faster than ever before. Needless lớn say, oil markets have been in turmoil and producers around the world are suffering.
Unfortunately, the atmospheric concentration of carbon dioxide, themost consequentialgreenhouse gas, has steadily climbed at the same time, along with global average temperature.
Note: Average global land-sea temperature anomaly relative lớn the 1961-1990 average temperature. Source: Our World in Data
The earth gets plenty of energy from the sun for all of us, even for our modern energy-intensive lives. The amount of solar energy that reaches habitable land is more than 1,000 times the amount of fossil fuel energy extracted globally per year. The problem is that this energy is diffuse. The sun that warms your face is definitely providing energy, but you need to lớn concentrate that energy to heat your home or move a vehicle.
renewable energyRenewable energy is from a source that is naturally replenished. (Ex: capturing wind using turbines or sunlight using solar cells does not change the amount of wind or sunlight that is available for future use.)
This is where modern giải pháp công nghệ comes in. Wind turbines & solar photovoltaic (PV) cells convert solar energy flows into electricity, in a process much more efficient than burning biomass, the pre-industrial way of capturing solar energy. Costs for wind & solar PV have been dropping rapidly & they are now mainstream, cost-effective technologies. Some existing forms of generating electricity, mainly nuclear và hydroelectricity, also don’t result in CO2 emissions. Combining new renewables with these existing sources represents an opportunity to lớn decarbonize — or eliminate CO2 emissions from — the electricity sector. Electricity generation is an important source of emissions, responsible for 27% of U.S. Greenhouse gas emissions in 2018.
However, unlike fossil fuels, wind and solar can only generate electricity when the wind is blowing or the sun is shining. This is an engineering challenge, since the nguồn grid operates in real time: power is generated và consumed simultaneously, with generation varying lớn keep the system in balance.
greenhouse gasA gas that traps heat in the earth’s atmosphere, including carbon dioxide, methane, ozone, & nitrous oxides.
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Engineering challenges beget engineering solutions, và a number of solutions can help. Power grids that cover a larger area are easier khổng lồ balance, given that if it isn’t windy or sunny in one location, it may be somewhere else. Demand-response strategies can encourage customers with flexibility in their processes khổng lồ use more nguồn when renewable power is available và to cut back when it isn’t. Power storage technologies can save excess electricity to be used later. Hydroelectric dams can serve this function now, and declining costs will make batteries more economic for nguồn storage on the grid. Storage solutions work well over a timeframe of hours — storing solar power to use in the evening, for example. But longer-term storage poses a greater challenge. Perhaps excess electricity can be used to lớn create hydrogen or other fuels that can be stored and used at a later time. Finally, fossil fuel generation often fills in the gaps in renewable generation today, especially natural gas generation, which can be efficiently ramped up & down to lớn meet demand.
Transforming solar energy flow into electricity is a clear place to start in creating a decarbonized energy system. A simple formula is khổng lồ decarbonize the electricity sector & electrify all the energy uses we can. Many important processes can be electrified — especially stationary uses, lượt thích in buildings & many industrial processes. To giảm giá khuyến mãi with climate change, this formula is the low-hanging fruit.
The two parts of this formula must proceed together. A shiny new electric vehicle in the driveway signals your concern about the environment to lớn your neighbors, but achieving its full potential benefit also requires a greener nguồn system. For today’s power nguồn system in the United States, and nearly everywhere in the world, electric vehicles provide emissions benefits, but the extent of those benefits varies greatly by location.Achieving the full potential benefit of electric vehicles would require a grid that supplies all renewable or zero-carbon power, something that no area in the United States consistently achieves today.
“Electrify everything” is a great plan, so far as it goes, but not everything can be easily electrified. Certain qualities of fossil fuels are difficult lớn replicate, such as their energy density and their ability to provide very high heat. Khổng lồ decarbonize processes that rely on these qualities, you need low-carbon fuels that mimic the qualities of fossil fuels.
The energy density of fossil fuels is particularly important in the transportation sector. A vehicle needs to lớn carry its fuel around as it travels, so the weight và volume of that fuel are key. Electric vehicles are a much-touted solution for replacing oil, but they are not perfect for all uses. Pound for pound, gasoline or diesel fuel contain about 40 times as much energy as a state-of-the-art battery. On the other hand, electric motors are much more efficient than internal combustion engines and electric vehicles are simpler mechanically, with many fewer moving parts. These advantages trang điểm for some of the battery’s weight penalty, but an electric vehicle will still be heavier than a similar vehicle running on fossil fuel. For vehicles that carry light loads and can refuel often, like passenger cars, this penalty isn’t a big deal. But for aviation, maritime shipping, or long-haul trucking, where the vehicle must carry heavy loads for long distances without refueling, the difference in energy density between fossil fuels and batteries is a huge challenge, and electric vehicles just don’t meet the need.
Gasoline carries much more energy per unit of weight than a battery. Agas-poweredcar with a 12.4-gallon tank carries77.5 pounds of gasoline.