User:Clayoquot/Sustainable energy

Sustainable energy by sector
Reducing the demand for energy is a key aspect of sustainable energy strategies.

Transport
Public transit, trains, cycling, urban planning, electric vehicles, fuel efficiency.

As an alternative to powering vehicles directly by electricity, electricity can be used to make hydrogen that hydrogen vehicles can burn. However, this is more expensive than using electricity directly, and wide-scale plans for a hydrogen economy have not come to fruition.

Aviation is one of the most difficult sectors to decarbonize because for storing a given amount of energy, batteries are much heavier than liquid fuels.

Modern biofuels can be used to power vehicles, but biofuel crops require a huge amount of land. David Mackay calculated that powering the vehicles for one lane of road in the UK would require a strip of land as long as the road but 8 km wide.

Buildings
Heating and cooling of buildings can be made far more efficient through use of heat pumps. Buildings can be designed and constructed with energy-saving features such as insulation and use of trees for shade. District heat, storage of heat and cold.

Research
Dramatically bringing down the cost of low-carbon energy would eliminate much of the need for politically difficult policies.

Areas of research: Energy storage, artificial photosynthesis...

Research is ongoing into nuclear technologies, including nuclear fusion that could potentially generate abundant cheap, zero-carbon electricity.

Relatively little attention has been paid to decarbonizing industry.

Trends
The costs of wind power, solar power, and battery storage have plummeted in recent years and are projected to continue falling. This trend could be disruptive.

There has been a trend of greater investment in wind and solar, however this rate of growth is far from sufficient to limit global warming to 1.50&deg;C. To accomplish this goal, the amount invested each year in low-carbon energy sources and energy efficiency would need to be approximately six times what was invested in 2015. The recent growth in renewables has not even been enough to keep up with the uptick in energy demand and the phase-out of nuclear power.

Policies
Talk about direct mandates around renewables, and direct subsidies to renewables Talk about fossil fuel subsidies

Current status
Providing sustainable energy is widely viewed as one of the greatest challenges facing humanity in the 21st century, both in terms of meeting the needs of the present and in terms of effects on future generations. Bill Gates said in 2011:

Worldwide, nearly a billion people do not have access to electricity. An estimated 3 billion people rely on traditional cookstoves and open fires to burn biomass or coal for heating and cooking. Air pollution, caused largely by the burning of fuel, kills an estimated 7 million people each year, including 4.3 million deaths caused by cooking with dirty fuels. The United Nations Sustainable Development Goals call for "access to affordable, reliable, sustainable and modern energy for all" by 2030.

Energy production and consumption are major contributors to climate change, being responsible for 72% of annual human-caused greenhouse gas emissions as of 2014. Generation of electricity and heat contributes 31% of human-caused greenhouse gas emissions, use of energy in transportation contributes 15%, and use of energy in manufacturing and construction contributes 12.4%. An additional 5.2% are released through processes associated with fossil fuel production, and 8.4% through various other forms of fuel combustion. As of 2015, 80% of the world's primary energy is produced from fossil fuels.

Where wood is used for cooking, serious local environmental damage, including desertification, can be caused by excessive harvesting. Promoting usage of cleaner fuels and more efficient technologies for cooking is therefore one of the top priorities of the United Nations Sustainable Energy for All initiative. Thus far, efforts to design clean cookstoves that are inexpensive, powered by sustainable energy sources, and acceptable to users have been mostly disappointing.

Current status
Worldwide, nearly a billion people do not have access to electricity, and around 3 billion people rely on dirty fuels for cooking. Air pollution from the burning of fossil fuels kills an estimated 3.61 million people each year. Energy production is a major contributor to climate change, being responsible for 72% of annual human-caused global greenhouse gas emissions as of 2013. As of 2015, 80% of the world's primary energy is produced from fossil fuels.

The United Nations Sustainable Development Goals call for "access to affordable, reliable, sustainable and modern energy for all" by 2030.

In developing countries

As of 2015, only 18% of the world's population consumes more than 120 GJ of energy per person per year, the amount needed to support "mature, affluent industrial societies".(Smil 2017b p. 416)

In 2015, the richest 10% of the world's population consumed 35% of the world's energy.(Smil 2017b p. 416) The poorest 5% of the world, living in 15 African countries, consumed just 0.2% of commercially-produced energy.(Smil 2017b p. 416)

Not important
As of 2010, the production and distribution of energy is responsible for approximately 35% of human-caused greenhouse gas emissions, making it the largest contributor of any sector.

Nuclear power
Nuclear power plants have been used since the 1950s to produce a steady supply of electricity, without creating local air pollution. In 2012, nuclear power plants in 30 countries generated 11% of global electricity. According to the IPCC, the median greenhouse gas emissions of nuclear power, including the mining and processing of their uranium fuel, are 12 gCO2eq per kWh, which is comparable to the rate of emissions from renewable energy sources. The debate over whether nuclear power can be considered sustainable revolves around the following issues:


 * Safety: The vast majority of nuclear power plants in current use are Second-generation, and require active cooling by water. For each unit of energy produced, nuclear power has caused xxx deaths, a record far better than fossil fuels and even some renewables. E.g. coal mining accidents, natural gas explosions, dam disasters. Fourth-generation nuclear power plants, which are expected to be commercialized in [timeframe], have design features that greatly reduce the possibility of a nuclear accident.
 * Cost and construction time: France, U.S., China
 * Radioactive waste: Quantity of waste and how long it lasts. Challenges in storing and transporting waste, and keeping terrorists from stealing it. [Some] fourth-generation produce very little waste (how much), and could use existing nuclear waste as fuel.
 * Nuclear proliferation: Overall record, India and Pakistan.

These concerns have led to a decrease in the contribution of nuclear energy to the global electricity supply since 1993. As of, few countries plan to expand their nuclear energy capability.

Traditional environmental groups such as Greenpeace and the Sierra Club are opposed to all use of nuclear power. The ecomodernist movement is in favour. Individuals who have described nuclear power as a green energy source include early Greenpeace member Patrick Moore,  George Monbiot, Bill Gates and James Lovelock.

Delete:


 * Some forms of nuclear power (ones which are able to "burn" nuclear waste through a process known as nuclear transmutation, such as an Integral Fast Reactor, could belong in the "Green Energy" category). Nuclear power plants can be more or less eliminated from their problem of nuclear waste through the use of nuclear reprocessing and newer plants as fast breeder and nuclear fusion plants.

Some people, including have specifically classified nuclear power as green energy. Others, including Greenpeace's Phil Radford disagree, claiming that the problems associated with radioactive waste and the risk of nuclear accidents (such as the Chernobyl disaster) pose an unacceptable risk to the environment and to humanity. However, newer nuclear reactor designs are capable of utilizing what is now deemed "nuclear waste" until it is no longer (or dramatically less) dangerous, and These designs have yet to be commercialized. (See: Molten salt reactor)

Footnote: A study by the Stanford University climatologist Marc Z. Jacobson estimated that the greenhouse gas emissions of nuclear power were xxx, based on several controversial assumptions (describe them).

Link to Passive nuclear safety

Refs
Edenhofer 2014:

Proposed pathways to sustainable energy
Some studies (who?) claim that 100% renewable energy, combined with energy conservation measures, can meet the energy needs of the world. Others (who?) argue that the models and assumptions used in these studies are flawed (such as what assumptions?), and that usage of some nuclear power will be necessary in order to meet global targets for reduction in fossil fuel use.

Other non-renewable energy sources
In theory, the greenhouse gas emissions of fossil fuel power plants can be significantly reduced through carbon capture and storage, although this process is expensive. Some believe that fossil fuel burning, with carbon capture and storage, may have a role in a sustainable energy system.

Overview
Growth in sustainable energy is critical for lifting people out of poverty - UN.

History and definitions
The concept of "sustainable development" was described by the World Commission on Environment and Development in its 1987 book Our Common Future. Its definition of "sustainability", now used widely, was:

"Sustainable development should meet the needs of the present without compromising the ability of future generations to meet their own needs."



Energy sources
For each energy source, discuss sustainability, and adoption trends.

Biomass and biofuel
Biomass is biological material derived from living, or recently living organisms. As an energy source, biomass can either be burned to produce heat and to generate electricity, or converted to various forms of biofuel. Liquid biofuels such as biodiesel and ethanol are especially valued as energy sources for motor vehicles.

Biomass is one of the most-used sources of renewable energy. It is available in many countries and is extremely versatile. When the biomass source is agricultural or municipal waste, burning it or converting it into biogas also provides a way to dispose of this waste.

As of 2012, wood remains the largest biomass energy source today. If biomass is harvested from crops, such as tree plantations, the cultivation of these crops can displace natural ecosystems and consume water resources, soil nutrients, and/or fertilizers. In some cases, such as the replacement of gasoline by corn-based ethanol, these impacts can actually result in higher overall carbon emissions.

Use of farmland for growing fuel can result in less land being available for growing food. Since photosynthesis is inherently inefficient, and crops also require significant amounts of energy to harvest, dry, and transport, the amount of energy produced per unit of land area is very small, in the range of 0.25 W/m2 to 1.2 W/m2. In Brazil, nearly 60% of sugar cane production is used to produce ethanol. In the United States, ethanol production has replaced less than 10% of motor gasoline use since 2011 but has consumed around 40% of the corn harvested in the country.

Biomass briquettes are increasingly being used in the developing world as an alternative to charcoal. The technique involves the conversion of almost any plant matter into compressed briquettes that typically have about 70% the calorific value of charcoal. There are relatively few examples of large-scale briquette production. One exception is in North Kivu, in eastern Democratic Republic of Congo, where forest clearance for charcoal production is considered to be the biggest threat to mountain gorilla habitat. The staff of Virunga National Park have successfully trained and equipped over 3500 people to produce biomass briquettes, thereby replacing charcoal produced illegally inside the national park, and creating significant employment for people living in extreme poverty in conflict-affected areas.

Biomass, biogas and biofuels are burned to produce heat/power and in doing so harm the environment. Pollutants such as sulphurous oxides (SOx), nitrous oxides (NOx), and particulate matter (PM) are produced from this combustion; the World Health Organisation estimates that 7 million premature deaths are caused each year by air pollution. Biomass combustion is a major contributor.

In developing countries, an estimated 3 billion people rely on traditional cookstoves and open fires to burn biomass for heating and cooking. This practice causes harmful local air pollution and increases danger from fires, resulting in an estimated 2 million deaths annually. Additionally, serious local environmental damage, including desertification, can be caused by excessive harvesting of wood and other combustible material. Promoting usage of cleaner fuels and technologies for cooking is therefore one of the top priorities of the United Nations Sustainable Energy for All initiative.



"Clean" fossil fuels

 * Coal + carbon capture and sequestration - does not have potential for lowering overall costs of energy.
 * Natural gas controversy.

Energy efficiency
Passive solar, passive building design