Heating and cooling energy demand and related emissions of the German residential building stock under climate change

The housing sector is a major consumer of energy. Studies on the future energy demand under climate change which also take into account future changes of the building stock, renovation measures and heating systems are still lacking. We provide the first analysis of the combined effect of these four influencing factors on the future energy demand for room conditioning of residential buildings and resulting greenhouse gas (GHG) emissions in Germany until 2060. We show that the heating energy demand will decrease substantially in the future. This shift will mainly depend on the number of renovated buildings and climate change scenarios and only slightly on demographic changes. The future cooling energy demand will remain low in the future unless the amount of air conditioners strongly increases. As a strong change in the German energy mix is not expected, the future GHG emissions caused by heating will mainly depend on the energy demand for future heating.     

Prospects of India's energy and emissions for a long time frame

For any nation, sector-wise forecasts of energy demand and emissions are becoming valuable elements in devising its national and international policies relating to energy security, local environment, and global climate change. It is in this context that this work attempts to forecast India's possible energy demands and emissions adopting a key indicator approach on least cost generation expansion optimization methodology for a long time frame. This study developed key indicators for useful-energy demand for end-use sectors such as industry, commerce, and residence. Key indicators for transport sector and non-energy use sectors were developed on transport mobility demand and end-use fuel demand. The main drivers of these key indicators are socio-economic parameters. This work was conducted in a linear programmed (LP) TIMES G5 model on TIMES modeling framework for model horizon of 1990–2100. By the end of the 21st-century, India's energy demands are projected to be about 1825 Mtoe of primary energy, 1263 Mtoe of final energy consumption, 4840 TWh of electricity generations, 723 Mtoe of energy import, and 4414 Mt of CO₂ emissions.     

A global coal production forecast with multi-Hubbert cycle analysis

Based on economic and policy considerations that appear to be unconstrained by geophysics, the Intergovernmental Panel on Climate Change (IPCC) generated forty carbon production and emissions scenarios. In this paper, we develop a base-case scenario for global coal production based on the physical multi-cycle Hubbert analysis of historical production data. Areas with large resources but little production history, such as Alaska and the Russian Far East, are treated as sensitivities on top of this base-case, producing an additional 125 Gt of coal. The value of this approach is that it provides a reality check on the magnitude of carbon emissions in a business-as-usual (BAU) scenario. The resulting base-case is significantly below 36 of the 40 carbon emission scenarios from the IPCC. The global peak of coal production from existing coalfields is predicted to occur close to the year 2011. The peak coal production rate is 160 EJ/y, and the peak carbon emissions from coal burning are 4.0 Gt C (15 Gt CO₂) per year. After 2011, the production rates of coal and CO₂ decline, reaching 1990 levels by the year 2037, and reaching 50% of the peak value in the year 2047. It is unlikely that future mines will reverse the trend predicted in this BAU scenario.     

Coal and energy security for India: Role of carbon dioxide (CO2) capture and storage (CCS)

Coal is the abundant domestic energy resource in India and is projected to remain so in future under a business-as-usual scenario. Using domestic coal mitigates national energy security risks. However coal use exacerbates global climate change. Under a strict climate change regime, coal use is projected to decline in future. However this would increase imports of energy sources like natural gas (NG) and nuclear and consequent energy security risks for India. The paper shows that carbon dioxide (CO₂) capture and storage (CCS) can mitigate CO₂ emissions from coal-based large point source (LPS) clusters and therefore would play a key role in mitigating both energy security risks for India and global climate change risks. This paper estimates future CO₂ emission projections from LPS in India, identifies the potential CO₂ storage types at aggregate level and matches the two into the future using Asia-Pacific Integrated Model (AIM/Local model) with a Geographical Information System (GIS) interface. The paper argues that clustering LPS that are close to potential storage sites could provide reasonable economic opportunities for CCS in future if storage sites of different types are further explored and found to have adequate capacity. The paper also indicates possible LPS locations to utilize CCS opportunities economically in future, especially since India is projected to add over 220,000 MW of thermal power generation capacity by 2030.     

Assessment of projected temperature impacts from climate change on the U.S. electric power sector using the Integrated Planning Model®

This study analyzes the potential impacts of changes in temperature due to climate change on the U.S. power sector, measuring the energy, environmental, and economic impacts of power system changes due to temperature changes under two emissions trajectories—with and without emissions mitigation. It estimates the impact of temperature change on heating and cooling degree days, electricity demand, and generating unit output and efficiency. These effects are then integrated into a dispatch and capacity planning model to estimate impacts on investment decisions, emissions, system costs, and power prices for 32 U.S. regions. Without mitigation actions, total annual electricity production costs in 2050 are projected to increase 14% ($51 billion) because of greater cooling demand as compared to a control scenario without future temperature changes. For a scenario with global emissions mitigation, including a reduction in U.S. power sector emissions of 36% below 2005 levels in 2050, the increase in total annual electricity production costs is approximately the same as the increase in system costs to satisfy the increased demand associated with unmitigated rising temperatures.     

On the potential trade-offs between energy supply and end-use technologies for residential heating

In Sweden, where district heating accounts for a significant share of residential heating, it has been argued that improvements in end-use energy efficiency may be counter-productive since such measures reduce the potential of energy efficient combined heat and power production. In this paper we model how the potential trade-offs between energy supply and end-use technologies depend on climate policy and energy prices. The model optimizes a combination of energy efficiency measures, technologies and fuels for heat supply and district heating extensions over a 50 year period. We ask under what circumstances improved end-use efficiency may be cost-effective in buildings connected to district heating? The answer hinges on the available technologies for electricity production. In a scenario with no alternatives to basic condensing electricity production, high CO₂ prices result in very high electricity prices, high profitability of combined heat and power production, and little incentive to reduce heat demand in buildings with district heating. In contrast, in a scenario where electricity production alternatives with low CO₂ emissions are available, the electricity price will level out at high CO₂ prices. This gives heat prices that increase with the CO₂ price and make end-use efficiency cost-effective also in buildings with district heating.     

The 2 °C scenario—A sustainable world energy perspective

A target-oriented scenario of future energy demand and supply is developed in a backcasting process. The main target is to reduce global CO₂ emissions to around 10 Gt/a in 2050, thus limiting global average temperature increase to 2 °C and preventing dangerous anthropogenic interference with the climate system. A 10-region energy system model is used for simulating global energy supply strategies. A review of sector and region-specific energy efficiency measures resulted in the specification of a global energy demand scenario incorporating strong energy efficiency measures. The corresponding supply scenario has been developed in an iterative process in close cooperation with stakeholders and regional counterparts from academia, NGOs and the renewable energy industry. The 2 °C scenario shows that renewable energy could provide as much as half of the world's energy needs by 2050. Developing countries can virtually stabilise their CO₂ emissions, while at the same time increasing energy consumption through economic growth. OECD countries will be able to reduce their emissions by up to 80%.     

Air conditioning in the region of Madrid, Spain: An approach to electricity consumption, economics and CO2 emissions

An understanding of electricity consumption due to residential air conditioning (AC) may improve production and environmental impact strategy design. This article reports on a study of peak and seasonal electricity consumption for residential air conditioning in the region of Madrid, Spain. Consumption was assessed by simulating the operation of AC units at the outdoor summer temperature characteristics of central Spain. AC unit performance when operating under part load conditions in keeping with weather conditions was also studied to find cooling demand and energy efficiency. Likewise final electricity consumption was computed and used to calculate energy costs and greenhouse gas emissions (GHGs). Cooling demand, when family holidays outside the region were factored into the calculations, came to 1.46 × 10⁹ kWh. Associated seasonal electricity demand was 617 × 10⁶ kWh and seasonal performance of AC units around 2.4. Electricity consumption in the whole region was observed to peak on 30 June 2008 at 5.44 × 10⁶ kW, being the load attributable to residential AC 1.79 × 10⁶ kW, resulting about 33% of the total peak consumption. The seasonal cost per household was about €156 and the total equivalent warming impact was 572 × 10³ t CO₂. The method proposed can be adapted for use in other regions.     

Quantitative analysis of energy-efficiency strategy on CO2 emissions in the residential sector in Japan – Case study of Iwate prefecture

This study examines the economics of energy-efficiency strategies for reducing CO₂ emissions in the residential sector in Japan from the perspective of regional characteristics. For this study, the residential sector in Iwate prefecture was selected as representative of rural areas in Japan. In order to promote purchases of energy-efficient consumer appliances, the prefectural government is presumed to reimburse purchasers a part of the cost difference between energy efficient and conventional appliances. This paper begins with a discussion of the prefecture’s financial support for purchasers of energy efficient appliances and assumes that the payments come from prefectural government funds. This paper then looks at the effect of a carbon-tax refund on the reduction of CO₂ emissions. The results show that, if half of the households use energy-efficient appliances, then CO₂ emissions in the residential sector in the year 2020 will decreases from the BAU scenario, 0.726 Mt-C to 0.674 Mt-C. However, the Iwate prefectural government expends $105 million annually, which is 1.5% of the total tax revenue in the year 2003. The carbon-tax refund effectively encourages further reductions in CO₂ emissions. Under the $20/tC carbon tax, proposed by the Ministry of the Environment, the carbon-tax refund leads to a reduction in residential CO₂ emissions from 0.726 Mt-C to 0.712 Mt-C.     

Hydrogen perspectives in Italy: Analysis of possible deployment scenarios

The paper analyses Italian hydrogen scenarios to meet climate change, environmental and energy security issues. An Italy-Markal model was used to analyse the national energy–environment up to 2050. About 40 specific hydrogen technologies were considered, reproducing the main chains of production, transport and consumption, with a focus on transport applications. The analysis is based on the Baseline and Alternative scenario results, where hydrogen reaches a significant share. The two scenarios constitute the starting points to analyse the hydrogen potential among the possible energy policy options. The energy demand in the Baseline scenario reaches values around 240 Mtoe at 2030, with an average annual growth of 0.9%. The Alternative scenario reduces consumption down to 220 Mtoe and stabilizes the _CO2${\mathrm{CO}}_2$ emissions. The Alternative scenario expects a rapid increase of hydrogen vehicles in 2030, up to 2.5 million, corresponding to 1 Mtoe of hydrogen consumption. A sensitivity analysis shows that the results are rather robust.     

Energy [R]evolution 2008—a sustainable world energy perspective

The Energy [R]evolution 2008 scenario is an update of the Energy [R]evolution scenario published in 2007. It takes up recent trends in global socio-economic developments, and analyses to which extent they affect chances for achieving global climate protection targets. The main target is to reduce global CO₂ emissions to 10 Gt per year in 2050, thus limiting global average temperature increase to 2 °C and preventing dangerous anthropogenic interference with the climate system. A review of sector and region specific energy efficiency measures resulted in the specification of a global energy demand scenario incorporating strong energy efficiency measures. The corresponding energy supply scenario has been developed in an iterative process in close cooperation with stakeholders and regional counterparts from academia, NGOs and the renewable energy industry. The Energy [R]evolution scenario shows that renewable energy can provide more than half of the world's energy needs by 2050. Developing countries can virtually stabilise their CO₂ emissions, whilst at the same time increasing energy consumption through economic growth. OECD countries will be able to reduce their emissions by up to 80%.     

Energy and emissions forecast of China over a long-time horizon

Forecasts of energy demand, the fuel mix meeting that demand and the associated emissions are a key requirement for informed energy planning and policy decisions to ensure energy security and address climate change. While there have been many studies on China focusing on the short and medium term (to 2020 and 2050) there is little in the literature focusing on the long term (to 2100). This paper seeks to address those gaps on sectoral energy demands and emissions on long term by following a two-stage approach. It develops key energy indicators on useful energy demand, transport mobility and end use fuel demand for various sectors. The main drivers of these indicators are socio-economic parameters. The indicators are used to project energy service demands and emissions forward for China in TIMES G5 model at least cost approach. The results from this reference scenario suggest that China will require approximately 4 Gtoe of primary energy, by the end of the 21st century to deliver 3 Gtoe final energy consumption, 10 PWh of electricity generation, 1.3 Gtoe of energy imports, which will results in 10 Gt CO₂ emissions.     

Green energies and the environment

Globally, buildings are responsible for approximately 40% of the total world annual energy consumption. Most of this energy is for the provision of lighting, heating, cooling, and air conditioning. Increasing awareness of the environmental impact of CO₂ and NO_x emissions and CFCs triggered a renewed interest in environmentally friendly cooling, and heating technologies. Under the 1997 Montreal Protocol, governments agreed to phase out chemicals used as refrigerants that have the potential to destroy stratospheric ozone. It was therefore considered desirable to reduce energy consumption and decrease the rate of depletion of world energy reserves and pollution of the environment. This article discusses a comprehensive review of energy sources, environment and sustainable development. This includes all the renewable energy technologies, energy efficiency systems, energy conservation scenarios, energy savings and other mitigation measures necessary to reduce climate change.     

Thermal performance and embodied energy analysis of a passive house – Case study of vault roof mud-house in India

This paper investigates thermal performance of an existing eco-friendly and low embodied energy vault roof passive house (or mud-house) located at Solar Energy Park of IIT Delhi, New Delhi (India). Based on embodied energy analysis, the energy payback time for the mud-house was determined as 18 years. The embodied energy per unit floor area of R.C.C. building (3702.3 MJ/m²) is quiet high as compared to the mud-house (2298.8 MJ/m²). The mud-house has three rooms with inverted U-shape roof and remaining three rooms with dome shape roof. A thermal model of the house consisting of six interconnected rooms was developed based on energy balance equations which were solved by using fourth order Runge Kutta numerical method. The predicted six room air temperatures were found in good agreement with the experimental observed data on hourly basis in each month for one year. The annual heating and cooling energy saving potential of the mud-house was determined as 1481 kW h/year and 1813 kW h/year respectively for New Delhi composite climate. The total mitigation of CO₂ emissions due to both heating and cooling energy saving potential was determined as 5.2 metric tons/year. The annual carbon credit potential of mud-house was determined as € 52/year. Similar results were obtained for the different climatic locations in India.     

International aviation emissions to 2025: Can emissions be stabilised without restricting demand?

International aviation is growing rapidly, resulting in rising aviation greenhouse gas emissions. Concerns about the growth trajectory of the industry and emissions have led to calls for market measures such as emissions trading and carbon levies to be introduced to restrict demand and prompt innovation. This paper provides an overview of the science on aviation's contribution to climate change, analyses key trends in the industry since 1990, projects international civil aviation emissions to 2025 and analyses the emission intensity improvements that are necessary to offset rising international demand. The findings suggest international aviation carbon dioxide (CO₂) emissions will increase by more than 110 per cent between 2005 and 2025 (from 416 Mt to between 876 and 1013 Mt) and that it is unlikely emissions could be stabilised at levels consistent with risk averse climate targets without restricting demand.     

Utilizing hydrogen energy to reduce greenhouse gas emissions in Canada's residential sector

An analysis of the potential to reduce greenhouse gas emissions in the residential sector by using hydrogen energy is reported. The residential sectors in provinces across Canada are considered. Greenhouse gas emissions are determined from the consumption of fossil fuels associated with the energy requirements in the residential sector. The use of hydrogen technologies in the residential sector is compared to conventional systems. The results are determined to vary by province, with the greatest attainable annual reductions in greenhouse gas emissions observed for heating to be in Alberta (7.2 t CO₂) and for power generation to be in Saskatchewan (7.2 t CO₂). The results suggest that hydrogen technologies for heating and power generation are promising options for reducing greenhouse gas emissions in Canada and its provinces.     

A local-scale low-carbon plan based on the STIRPAT model and the scenario method: The case of Minhang District,Shanghai, China

To achieve a goal of reducing the emission intensity of carbon dioxide in 2020 by 40–45% relative to 2005 in China, the framework for a low-carbon scenario was developed on a small scale in Minhang District, Shanghai. The STIRPAT model was employed to reveal the factors that contribute to CO₂ emissions in this district: the increase of population, affluence and urbanisation level would increase CO₂ emissions, but energy intensity would decrease. Stakeholder involvement was another key component of the framework, and in this case, several rounds of negotiation and feedback resulted in fifteen final scenarios with the estimations of CO₂ emissions in 2015. For the low-carbon development plan of Minhang District, the model considered the actual capacity and development potential of this district, the best scenario combining with the high rates of affluence growing and energy intensity reducing as well as the middle rates of population growth and urbanisation level. The final CO₂ emissions of this scenario were 66.1 Mt in 2015. Based on these results, strategic suggestions have been proposed to reduce future energy intensity in Minhang District through industrial and energy resource structure reformation, lifestyle change and the transportation system improvement in this district.     

Constraints of fossil fuels depletion on global warming projections

A scientific debate is in progress about the intersection of climate change with the new field of fossil fuels depletion geology. Here, new projections of atmospheric CO₂ concentration and global-mean temperature change are presented, should fossil fuels be exploited at a rate limited by geological availability only. The present work starts from the projections of fossil energy use, as obtained from ten independent sources. From such projections an upper bound, a lower bound and an ensemble mean profile for fossil CO₂ emissions until 2200 are derived. Using the coupled gas–cycle/climate model MAGICC, the corresponding climatic projections out to 2200 are obtained. We find that CO₂ concentration might increase up to about 480 ppm (445–540 ppm), while the global-mean temperature increase w.r.t. 2000 might reach 1.2 °C (0.9–1.6 °C). However, future improvements of fossil fuels recovery and discoveries of new resources might lead to higher emissions; hence our climatic projections are likely to be underestimated. In the absence of actions of emissions reduction, a level of dangerous anthropogenic interference with the climate system might be already experienced toward the middle of the 21st century, despite the constraints imposed by the exhaustion of fossil fuels.     

Expected impacts on greenhouse gas and air pollutant emissions due to a possible transition towards a hydrogen economy in German road transport

Transitioning German road transport partially to hydrogen energy is among the possibilities being discussed to help meet national climate targets. This study investigates impacts of a hypothetical, complete transition from conventionally-fueled to hydrogen-powered German transport through representative scenarios. Our results show that German emissions change between ?179 and +95 MtCO₂eq annually, depending on the scenario, with renewable-powered electrolysis leading to the greatest emissions reduction, while electrolysis using the fossil-intense current electricity mix leads to the greatest increase. German energy emissions of regulated pollutants decrease significantly, indicating the potential for simultaneous air quality improvements. Vehicular hydrogen demand is 1000 PJ annually, requiring 446–525 TWh for electrolysis, hydrogen transport and storage, which could be supplied by future German renewable generation, supporting the potential for CO₂-free hydrogen traffic and increased energy security. Thus hydrogen-powered transport could contribute significantly to climate and air quality goals, warranting further research and political discussion about this possibility.     

Energy harvesting, reuse and upgrade to reduce primary energy usage in the USA

Two-thirds of input energy for electricity generation in the USA is lost as heat during conversion processes. Additionally, 12.5% of primary fuel and 20.3% of electricity are employed for space heating, water heating, and refrigeration where low-grade heat could suffice. The potential for harnessing waste heat from power generation and thermal processes to perform such tasks is assessed. By matching power plant outlet streams with applications at corresponding temperature ranges, sufficient waste heat is identified to satisfy all USA space and water heating needs. Sufficient high temperature exhaust from power plants is identified to satisfy 27% of residential air conditioning with thermally activated refrigeration, or all industrial refrigeration and process heating from 100 to 150 °C. Engine coolant and exhaust is sufficient to satisfy all air conditioning and 68% of electrical demands in vehicles. Overall, this study demonstrates the potential to reduce USA primary energy demand by 12% and CO₂ emissions by 13% through waste heat recovery. A detailed analysis of thermal energy demand in pulp and paper manufacturing is conducted to demonstrate the methodology for improving the fidelity of this approach. These results can inform infrastructure and development to capture heat that would be lost today, substantially reducing USA energy intensity.