By how much and by when can we reduce our energy use?

What is the policy on buildings?

What is thermal comfort?

How might a national refurbishment scheme be financed?

What are the current carbon emissions from transport?

How much energy can we save in the transport sector and how?

Why electric vehicles?

Why not use hydrogen for cars?

Why can’t we run all transport on biofuels?

Can people still fly?

What about all the heavy metals / minerals that we’ll need for the batteries? I heard they’re already running out?

Why is behavioural change important? Can’t we just solve the problem with technology?

By how much and by when can we reduce our energy use?

Decades of access of abundant cheap fossil fuels have created an energy inefficient society.Through a combination of reducing energy use and improving energy efficiency zerocarbonbritain2030 demonstrates how we can reduce our energy demand by 56% by 2030 and that remaining energy could be generated using renewable technologies.

What is the policy on buildings?

Britain’s building stock is ill-prepared for an energy lean future.Efforts need to be made to increase the energy efficiency of both new-build and existing buildings.It is far more cost-effective to design energy demand out of buildings than to invest in new energy supplies

There is already a range of legislation governing the construction industry covering issues such as sustainability, energy efficiency and carbon emissions. However, the government needs to ensure that there is greater consistency between standards, a clear definition of “zero carbon”, and that regulations are enforced.

There is a strong need for the government to institute a national refurbishment scheme, in particular to improve the insulation levels of homes.Standards for refurbishment should be written into a Code for Sustainable High-Performance Refurbishment.Government can support the development and roll-out of various payment schemes, subsidies and financial incentives (see How might a national refurbishment scheme be financed?).

Energy is consumed through the construction and maintenance of buildings as well as through their use.While current practice often focuses on energy “in use”, material selection should take into account the embodied energy of materials in determining preferred choice.It is even possible to select building and refurbishment materials that sequester carbon. Constructions that use natural materials absorb CO₂ from the atmosphere, by making buildings from wood, straw and other natural materials can lock away millions of tonnes of CO₂ each year.

What is thermal comfort?

Improving the energy efficiency of space heating is critically important to reducing emissions from the building sector. In 2007, space heating accounted for 56% of domestic energy consumption and 46% of service sector energy consumption.

The concept of “thermal comfort” offers us an alternative way of thinking about heating in buildings. Thermal comfort is defined as “a mental condition that is based upon the lack of perception of noticeable changes in temperature that results in a personal expression of satisfaction with the environment”. It reminds us that increasing the air temperature of a room is not the only way of making the room feel comfortable. For example, transition spaces such as corridors often do not need to be the same temperature as living rooms to feel warm.Intelligent building design can automatically adjust the heating in such transition spaces. Draughts and temperature differentials between outside and inside the home both affect how comfortable people feel.Of course another way of maintaining a comfortable level of warmth without turning up the heating is to wear a jumper!

How might a national refurbishment scheme be financed?

Refurbishment at scale and in one location, e.g. through a street-by-street approach, dramatically reduces the cost. This requires cooperation and buy-in from homeowners, probably alongside some form of public-private partnership to plan its implementation.

A range of financial incentives can be offered to homeowners and occupiers to increase the cost-effectiveness of refurbishment and reduce or eliminate the up-front costs. These should be provided alongside public education and advice schemes which inform the public about energy use and provide assistance in choosing appropriate financing mechanisms.

Low-interest loans or green mortgages which provide lower interest rates for energy efficiency investments can be offered.Further financial incentives might include stamp duty or council tax rebates for existing properties that have had energy efficiency improvements made, and lower VAT on energy efficient products or services.

Pay-as-you-save (PAYS) is an alternative subsidising method that removes the need for home owners or occupiers to provide up-front financing. A low energy refurbishment provider uses finance, from a third party to cover the upfront costs of the low energy work. A repayment tariff is then linked through a meter to the property over an extended period of time. Customers who sign up to a PAYS tariff benefit financially because the repayment tariff is set up to cost less than the amount of energy saved. The payment obligation is attached to the property rather than a specific owner or occupant, so if people move, they do not have to pay for the efficiency savings that they are no longer benefiting from.

An alternative finance model offers installers the ability to capture the energy bill savings. This would enable the initial capital to come from a variety of interested parties.The emergence of Energy Supply Companies (ESCOs) is one example of such an approach. Within this approach, a customer pays the ESCO to keep their dwelling at a set temperature throughout the year, rather than per unit of energy used. The ESCO is therefore incentivised to invest in efficiency measures.

What are the current carbon emissions from transport?

The transport sector currently accounts for around 24% of UK domestic emissions, producing approximately 130 million tonnes of CO₂ per annum. Including the UK’s share of international aviation and shipping adds another 43 million tonnes, and increases transport’s overall share of the nation’s total CO₂ emissions to 32%.

The greatest transport carbon emissions come from passenger cars and international aviation.Planes also release water vapour and nitrogen oxides at high altitudes where they have a short-term warming effect which they do not have when released at ground level.

Emissions from heavy goods vehicles (HGVs) and light goods vehicles (LGVs) also contribute a significant proportion to total emissions.Public transport modes such as buses and rail have minor carbon impacts.The majority of carbon emissions from transport can be shown to be from medium- and long-distance trips.

How much energy can we save from the transport sector and how?

zerocarbonbritain2030 demonstrates a 63% reduction in energy use for transport. The remaining energy is supplied through decarbonised sources.

Reductions in energy use and emissions will be achieved in numerous ways, including:

• The use of new fuels, mainly electricity but supplemented with a mix of a small amount of hydrogen and biofuels.

• Improved efficiency of vehicles through better design.

• A modal shift away from private transport towards public transport, incentivised through investment in low carbon, accessible, reliable and cheap public transport, and supported by a range of behavioural change projects to engage the public and better urban planning.

• The development of new business models that encourage lower fuel use for private vehicles, including car clubs, pay-as-you-go insurance, and car leases per mile.

• A modal shift for freight from road to rail and sea, with better interchange facilities at ports.

Why electric vehicles?

Electric vehicles are one of the most direct ways of decarbonising the transport system. Their emissions are slightly lower than petrol cars even with the current grid mix, and will reduce close to zero if the electricity used to power them is produced from renewable sources. The government should continue to support the development and roll-out of electric vehicles. Further development of battery technology is likely to provide increased range, lower cost and shorter recharge times.

The roll-out of electric vehicles suggests significantly increased electric demand. However, with the use of smart meters and smart charging for electric cars, electric cars may require little or no additional electricity capacity. Cars could be set to charge when demand for electricity is low – for example, during the night - preventing any increase in peak demand.

It is not just personal cars that can be electrified; electricity also has a major role to play for rail, HGVs and other transport modes. Public transport (much of which will be electrified) will probably prove more cost-effective than personal electric cars. Other options, such as car leasing and community cars clubs, can also reduce the number of cars on the road.

Why not use hydrogen for cars?

Using electricity to make hydrogen is much less energy efficient than storing it in batteries - it uses about double the amount of energy to run a vehicle on such hydrogen as it does to run it on batteries. For cars it is therefore more efficient to use batteries.

However, the advantage that hydrogen has over conventional batteries is that it can store more energy for less weight. This makes it more suitable for certain types of vehicles, generally the larger, heavier vehicles which require a great deal of power. In the scenario we use electricity directly where we can, and hydrogen and biofuel for those vehicles which cannot run directly on electricity.

Why can’t we run all transport on biofuels?

It would not be feasible to run all transport on biofuels. There is not enough land to grow them on.

As is now widely known, biofuels are beset by serious issues. At an international scale they have been linked to negative impacts on deforestation, food and water availability, gender inequity and the loss of land tenure for the poor (although depending on the implementation they can also have beneficial consequences for the poor, as they can provide income for poor farmers).

We do not use biofuels in the scenario where there are alternative low carbon solutions, such as renewably powered electricity. However there are some areas for which it is very difficult to find an alternative to liquid fuels. In the scenario we use indigenously grown “second generation” biofuels in the cracks to lubricate the system, and for those areas where there is no other non-fossil fuel alternative.

It should be noted that we have used a theoretical model that involves (largely) drawing a boundary around the British Isles and determining what can be done with our land mass in isolation from the rest of the world. This is a very useful exercise and is important for gaining an understanding of the issues. However it does mean that some issues to do with how Britain integrates with the rest of the world have been placed beyond the scope of the report.

Can people still fly?

Yes – but aviation will be reduced. The expansion of high-speed, frequent rail and sea services will see a dramatic reduction in domestic and short-haul flights. Train, ferry and coach fares would become cheaper, more frequent and more accessible.

In moving towards a zero carbon economy there seem to be no easy fixes for international aviation. While improvements in efficiency are possible through for example, optimising air traffic routes, using electric motors while taxiing, and new designs such as the Blended Wing Body - it is very hard to decarbonise the sector altogether as it is not possible to electrify planes.

A number of airlines are currently researching synthetic fuels and hydrogen as a zero-carbon alternative to existing fuels. Hydrogen is a potential zero-carbon alternative. However, it would emit water vapour - a potent greenhouse gas if released at high altitudes - directly into the atmosphere.

Biofuels can also be used to power jet engines. Within our zerocarbonbritain2030 scenario, we suggest that land area made available through reduction in grazing livestock will allow us to retain one third of current aviation levels, as well as powering shipping, some farm machinery and a few other areas for which it is currently hard to find an alternative to liquid hydrocarbon fuels. 1.7 million hectares of short rotation coppice in the UK provide the biofuel, and about a third of the total biofuel produced from this area is biokerosene to fuel planes. 1.7 million hectares is a very significant area of land.

What about all the heavy metals / minerals that we’ll need for the batteries? I heard they’re already running out?

This is a myth. It appears to have originated largely from a single source (William Tahil).

Lithium – the key resource needed for batteries - is in fact extremely abundant and in no danger of running out any time soon, although deposits are concentrated in certain areas of the globe. It is also worth noting that it is possible to recycle it from exhausted batteries.

Why is behavioural change important? Can’t we just solve the problem with technology?

Technology will be a critical part of the solution to climate change and energy insecurity.In zerocarbonbritain2030, we show that Britain can achieve net-zero emissions by 2030 using current technology. We also advocate the continued research, development and application of new technologies, that could help make the decarbonisation process easier, fairer and quicker.

However technology does not function in a vacuum. Whether simple or advanced, technology will only ever be of value if we choose to promote its development and use by introducing supporting legislation and economic drivers, and by changing our attitudes and behaviours so that we are working with technology to reduce our emissions, not against it. Becoming zero carbon is a challenge and it will require technology and significant behavioural change.

We don’t know if there will one day arise some easy technical fix to climate change.But the issue is too urgent to wait and hope. We need to act now.