In many parts of the United States, installing a wind or solar farm is now cheaper than simply buying fuel for an existing generator on fossil fuels. And that changes the electricity market in the US dramatically and requires many people to update previous forecasts. This motivated a group of researchers to look at the costs and challenges of the entire US towards carbon neutrality.
By building a model of the US-wide energy market, the researchers investigated what it would take to reach the country by 2050 where energy consumption had no net emissions – and they even looked at a scenario where the emissions are negative. They found that, as you would expect, costs would drop dramatically to less than 1 percent of GDP, even before the costs they avoided were calculated by preventing the worst effects of climate change. And as an added bonus, we pay less for our power.
But the modeling also suggests that this end result will have rather unusual features; we will need carbon capture, but it will not be attached to power plants, for example.
Model all the things
Decent models of the future energy economy are complicated. This usually involves setting the grid by region and simulating the typical question using historical data, which is often scaled to represent a larger question. They will then try to meet the demand by using different energy sources, subject to a number of applied restrictions. So, in this case, limiting carbon emissions is obviously one of the limitations. The model then repeats over possible ways to meet the demand and constraints in the most economical way possible, and identifies an optimal solution.
In this case, the researchers draw up a series of eight scenarios that apply different constraints. These include things like the ongoing current trends in the future, a scenario where fossil fuel prices are low, and one that merely identifies the cheapest carbon-neutral route. Other variations include a fully renewable network and high levels of efficiency technology, another where the land given over to energy production is limited and one where the United States can achieve negative net emissions.
The US uses fossil fuels for many things outside of electricity generation, and shifting them to emission-free options is also part of the model. These include things like switching from vehicle and heating to electrical options and changing industrial processes where possible. Carbon capture is expected to be used to achieve the emission targets.
One of the things that immediately becomes apparent from running the business-like-normal model is how much has already changed thanks to the price drop in wind and solar power. In this scenario, carbon emissions will fall by 22 percent, mainly due to the shift in coal use. It is worth knowing, as all suggestions for a target in the area can be dismissed as irrelevant. Another thing that is clear is that the carbon emissions from the energy system do not mean that the US will eliminate greenhouse gas emissions. The greenhouse gases that do not contain carbon still produce 500 metric megatons of carbon dioxide.
Efficiency and beyond
One of the things that the research makes clear is that efficiency will be absolutely essential to achieve emissions targets. By 2050, the rising population and GDP should boost energy demand without being effective. But to achieve carbon neutrality, we need to keep energy consumption roughly equal to our current levels. Some efficiency will occur simply because electric vehicles and heating systems are inherently more efficient. But it is clear that we will need much more, as the research team estimates that per capita energy consumption will have to fall by about 40 percent over the next 30 years to achieve carbon neutrality.
Although energy consumption may remain the same, the increased electrification of homes and vehicles will mean that we will have to significantly increase the generation capacity. The typical scenario involves about 3.2 terawatts of new capacity, almost all in the form of wind and solar power.
The good news is that it’s relatively inexpensive. The researchers estimate that the net cost of the transformation by 2050 will total $ 145 billion, which is less than half a percent of GDP in that year. This figure does include the increased savings on electric heating and vehicles, which offset part of their costs. But that does not include the reduced cost of climate change or lower spending on health care due to the reduced use of fossil fuels. These savings will be significant, and it will almost certainly go beyond reimbursing the cost.
Due to the lower cost of renewable energy generation, the authors plan that we will also spend less on total electricity.
The most expensive scenarios increase costs to about 1 percent of 2050 GDP. It is especially the most expensive to go to net negative emissions; Instead, the use of soil pruning limits the amount of renewable energy that can be used, which increases costs.
Part of the reason it’s so cheap is because it’s not necessary to replace viable hardware. Everything that needs to be taken out of use, from coal generators to hot water heaters, has a limited lifespan. The researchers calculate that replacing everything with renewable or high-efficiency electrical versions will complete the transition within sufficient time.
Not what you would expect
Many people adopt a carbon-neutral grid, and assume that periods of low solar and wind production are smoothed with gas generators using carbon capture and storage. But this analysis suggests that any remaining gas plants simply will not work often enough to provide an economic justification for the carbon capture hardware. Similar things are true with batteries; it is expected that the periods in which demand exceeds capacity are so scarce that it does not make sense to build so many batteries to cover it.
Instead, gas plants will simply dump their carbon emissions into the air. It’s ultimately carbon neutral because we still need liquid fuel for things like air transport, and we’ll make it pull carbon out of the atmosphere, combined with hydrogen produced from water during periods of excessive renewable supply. The researchers estimate that we need 3,500 terawatts to make just hydrogen – about the same amount of electricity we currently make.
“Until recently, it was unclear whether variable renewable energy, nuclear or fossil fuels with carbon capture and storage would be the main form of generation in a carbon system … The decline in the cost of variable renewable energy over the past few years has however, the situation finally changed. ”
The scenarios with additional constraints also yield odd results. The only scenario in which nuclear power makes economic sense is the land in which land use is limited. It also drives more wind abroad and is dependent on fossil-fuel fossil fuel plants. It is not surprising that this is the most expensive situation the researchers have looked at. Carbon capture, coupled with the improved use of biomass for power, is also prominent in a scenario where the shift to electric vehicles and appliances is delayed.
Being completely renewable actually forces much higher levels of carbon capture to ensure that fuel needs can be met without any fossil fuel. And to be negative, involves a variety of carbon capture and biofuels, with significant land use due to the latter.
Everything has changed
To some extent, the researchers themselves seem somewhat surprised at how much has changed over the past few years. “The net cost of deep carbon dioxide, even reaching a 1 ° C / 350 ppm orbit,” they write, “is significantly lower than the estimates for less ambitious 80 percent by 2050 scenarios a few years ago.” It also provides clarity on what an uncertain future was. “Until recently, it was unclear whether variable renewable energy, nuclear power or fossil fuel with carbon capture and storage would be the most important form of generation in a carbon system,” they note. “However, the decline in the cost of variable renewable energy over the past few years has definitely changed the situation.”
Even if we will invest in the future now, even if we go deep into the carbon dioxide. It will cost money to get there, but we have lower future energy costs if we pay the price in advance, as well as improved health and a more stable climate.
However, there are important obstacles to getting there as a simple economy. In the release of free future, we will install about 160 GW of wind and solar power per year in less than two decades; In 2021, we will only install 15GW. And the switch to electric vehicles and appliances has to start now – everything that breaks has to be replaced by an electric version, which apparently does not happen.
But if this analysis persists, there are good reasons to think it’s worth getting started.
AGU Advances, 2021. DOI: 10.1029 / 2020AV000284 (On DOIs).