Navigant Research Blog

Green House Gas Emissions and HVAC

— June 9, 2015

The scientific consensus around climate change is that greenhouse gases (GHGs) emitted by human activities are creating a very serious problem. As a result, most major global regions have adopted targets for reduction of GHG emissions, notably carbon dioxide (CO2). The largest source of CO2 emissions comes from the burning of fossil fuels for generating electricity, powering vehicles, and providing heat. Heating, ventilation, and air conditioning (HVAC) equipment plays a large role in CO2 emissions, as it accounts for roughly 40% of total building energy consumption.

Thus, increasing the efficiency of HVAC equipment is a clear way to address GHG emissions. But, it’s not the only way HVAC equipment can help. Indeed, in a recent report, the World Resources Institute points out that non-energy and non-CO2 emissions account for 22% of all U.S. GHG emissions and are expected to rise. The report goes on to recommend the reduction of hydroflourocarbons (HFCs), which are used as refrigerants in HVAC equipment. However, when it comes to HVAC, what HFCs should be replaced by is not entirely clear.

Engineering Requirements

Within an HVAC system, refrigerant needs to be evaporated, condensed, and be compressed in such a way that the system can provide cool air. As a result, the band of temperature and pressure in which refrigerant changes phase between liquid and gas is narrow. Within a building, even the best HVAC systems may leak at some point in their lifetime. So, refrigerant needs to be non-toxic and non-flammable to keep building occupants safe. These requirements were met by chlorofluorocarbons (CFCs) and hydrochlorofluorocarbons (HCFCs). However, the proliferation of these refrigerants introduced a new problem: ozone depletion. While HFCs have solved the problem of ozone depletion, they are a GHG that traps heat in the atmosphere, contributing to climate change. The next generation of refrigerant needs to solve all of these problems.

So far, finding one refrigerant that is functional, safe, and doesn’t have severe impacts on the environment has been difficult. Potential candidates that have a lower the global warming potential than HFCs include R-32, which is mildly flammable, and CO2, which doesn’t fully change phase. Both have been commercialized. R-32 has been available in Japan since 2012. CO2 is being used as a standalone refrigerant in Europe and has recently been deployed in the United States. While challenges still remain, the development of these refrigerants presents the promise of reduced GHG emissions.

 

California Drought Implications for Electric T&D Becoming Clearer

— June 2, 2015

The implications of climate change and the 4-year California drought are just beginning to become clear. The snowpack in the Sierras, where reservoirs and dams ultimately feed the canal system that delivers water to the Bay Area, the Central Valley, and Southern California, is at an all-time low. While strict water rationing is mandatory for some residential and commercial consumers in many parts of the state, there are other forces at play. Some are laudable, and some are not.

On one hand, many city and municipal water districts are offering new rebate programs and incentives to remove lawns that require watering and replace them with xeriscape landscapes that require little if any water. On the other hand, the agricultural economy in California’s Central Valley needs water for almonds, pistachios, and a host of other products, and the large farms are reportedly pumping down the aquifers to support their business.

Thinking Long Term

Prolonged drought could also have major effects on the electric transmission and distribution (T&D) system, as well as on the water delivery system across California.

  • The major water agencies, including the Association of California Water Agencies (ACWA) managing the canal system between Northern and Southern California, have for many years been not only a major end-use consumer, but also a demand response resource for the California Independent System Operator (CAISO).  If the volume of water moving south through the Central Valley and over the mountains into the Los Angeles basin decreases substantially, the loss of demand response resources during peak demand conditions could be substantial.
  • With limited snowpack, major California reservoirs are now at record low levels and have limited, if any, hydropower capacity. Innovative pumped water storage projects like Pacific Gas and Electric’s (PG&E’s) Helms System, which uses off-peak Diablo Canyon nuclear power to pump water up for day-time generation use, will be at risk.
  • Recent reports in media have suggested that many locations in California’s Central Valley are sinking as a result of ongoing water pumping from the underground aquifers by all types of commercial and agricultural businesses. Not only are residential, commercial, and agricultural wells going dry, but the land itself is subsiding. This has tremendous implications for California’s Peripheral Canal system and other longstanding canals that transport water north to south through the central valley. As subsidence occurs, it is entirely possible that cement canals will fracture, and major leaks will occur, further exacerbating the water loss problem.

As in many states, the electric transmission infrastructure in California is aging. It’s clear that California’s drought will have a significant effect on the electric power market as well, degrading demand response resources, electric demand for water pumping, and hydropower resources.

 

Following Election, U.K. Renewables Policy Plans Come to Light

— June 2, 2015

A couple of weeks after a surprising result in the United Kingdom’s parliamentary election, in which the Conservative Party won a majority, plans for the government’s renewable energy policies are becoming clearer. Although the Conservative Party has governed for the last 5 years, it was part of a coalition, so there is a possibility that significant policy changes will occur.

Amber Rudd Takes the Lead

On May 11, Prime Minister David Cameron appointed Amber Rudd as the United Kingdom’s new Secretary of State for Energy and Climate Change, which was well-received by the renewable energy industry. The renewable energy trade bodies in the United Kingdom (Renewable Energy Association, RenewableUK, and the Solar Trade Association) appeared to have good comments about Rudd, and Nina Skorupska, the chief executive of the Renewable Energy Association, had the following comments on Rudd’s appointment.

“Amber Rudd has been a champion of renewables and the low-carbon economy in the past year, and her appointment will do much to allay the fears some may have after the general election … ensuring we meet our targets in the most efficient way … and making sure the UK is leading the way in green jobs and cost effective renewables.”

While RenewableUK, which mainly represents the wind industry, criticized the Conservatives’ manifesto when it was launched, its chief executive, Maria McCaffery, was also pleased by the appointment of Rudd. In a note released to the press, McCaffery said:

“We welcome the positive commitments which she has made on reducing emissions, tackling climate change and protecting the environment. We are looking forward to working with her and showing how all the technologies we represent: onshore wind, offshore wind and wave & tidal energy, can help achieve these aims.”

Onshore Wind on the Chopping Block

The Conservatives’ manifesto included a promise to stop incentives for onshore wind farms and to give local residents more influence in planning approval of the projects. In an interview with the Sunday Times this week, Rudd reiterated the Tories’ manifesto pledge to effectively end the development of new wind farms on U.K. land, outlining her hopes for the new measures to come into force by May 2016. While onshore wind in the United Kingdom can be competitive with fossil generation, the additional requirements to develop a project, like signing a power-purchase agreement, and survive what would be a gruesome planning application process, carry extra risks that few investors would like to face. This is expected to affect Navigant Research’s U.K. wind energy forecast, which is part of the World Wind Energy Market Update 2015 report.

Currently, there are about 7 GW of onshore wind capacity under development. While the onshore wind utility-scale installations are expected to decline, there will be room for companies willing to participate in community-scale projects. Community projects have the double advantage of a guaranteed buyer for the electricity produced while getting local support for the project by sharing the benefits of the wind farm.

A Solar Revolution Underway

While at first look this looks like a step back for the renewable industry, in reality, the winners if this policy is implemented would be all other sectors within the industry. In another interview, Rudd said she hopes to “unleash a new solar revolution” as a government cabinet minister. This seems feasible given that solar PV would become the cheapest source of renewable energy that can be deployed at scale. Other sectors will benefit as well. Some biomass projects would become competitive, and even offshore wind would benefit if the bids in the Contract for Difference (CfD) increase.

 

(Geo)Engineering a Climate Change Solution

— March 5, 2015

Climate engineering, or geoengineering, refers to the deliberate and large-scale intervention in the Earth’s climatic systems with the goal of reducing the effects of global warming. While I would argue that mitigation and fossil-fuel emissions reductions should be the primary course of action on climate change, it is also undeniable that achieving concerted and coordinated political action has been monumentally difficult. As outlandish as some geoengineering proposals may sound, changing the behavior of billions of people and overcoming the basic political and industrial challenges of drastically reducing fossil fuel consumption may prove to be even more difficult.

Although significant progress has certainly been made globally in the areas of renewable energy generation, energy efficiency, and improving transportation efficiencies, the international community as a whole has thus far failed to design and agree upon policies that will drastically reduce the amount of CO2 released into the atmosphere in any climate-impactful way.

More Research Needed

This lack of progress on climate change through emissions reductions leads to the conclusion that other approaches should at least be considered and adequately studied to determine efficacy. In early February, a panel of scientists at the National Academy of Sciences released a report arguing that more research on geoengineering needs to be conducted in order to better understand the associated risks and potential benefits. President Obama’s science advisor also publicly backed the initiative in 2010.

There are at least seven geoengineering proposals that are currently being hypothesized as potential climate intervention strategies:

  • Spraying sulfate aerosols into the atmosphere: While risky due to possible ozone layer deterioration, the idea is to reduce the Earth’s absorption of sunlight (much like ash from volcano eruptions).
  • Trapping CO2 in carbon scrubbers: Researchers at Columbia University are working on a carbon scrubber that would remove 1 ton of CO2 from the atmosphere per day. Projected to be available in 2 years, such scrubbers would cost $200,000 apiece, according to the Columbia scientists.
  • Fertilizing trees with nitrogen: This would theoretically increase the trees’ ability to absorb CO2.
  • Aerial Reforestation: Battling rampant deforestation, and the resultant loss of CO2 absorption capacity, airplanes would drop tree seedlings encased in biodegradable containers over large areas of land.
  • Adding powered limestone to the oceans: Such schemes would attempt to reduce ocean acidity and increase carbon sequestration.
  • Ocean iron fertilization: This process would increase the rate of photosynthesis in phyto-plankton in order to absorb more CO2.
  • Enriching soils with biochar: Biochar, a fine-grated charcoal that is highly resistant to decomposition, would hypothetically enrich soils and soak up excess CO2.

This is by no means an exhaustive list of proposals; reflecting sunlight back into space and many other ideas exist. However, it should be noted that there are also many legitimate controversies around geoengineering proposals. Spraying sulfate aerosols into the atmosphere, for example, could degrade the ozone layer. Many of the proposals are too expensive, and most offer an imperfect fix–even if the global average temperature of the earth is reduced, nothing would be done to stop the other consequences of fossil fuel burning such as ocean acidification and air pollution.

While no one knows for sure which  geoengineering proposals offer the most promise, I would argue that they should at least be more openly debated and further researched as a possible climate solution (particularly for a crisis situation where the reduction in CO2 needs to be immediate). Unfortunately, the international community has thus far made very little progress in addressing one of the world’s most serious problems, and in the case of climate change, we are in no position to reject promising ideas out of hand.

 

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