Hydropower for sustainable water and energy development

Turkey has a total gross hydropower potential of 433 GWh/year, but only 125 GWh/year of the total hydroelectric potential of Turkey can be economically used. By the commissioning of new hydropower plants, which are under construction, 36% of the economically usable potential of the country would be tapped. Turkey presently has considerable renewable energy sources. The most important renewable sources are hydropower, biomass, geothermal, solar and wind. Turkey's geographical location has several advantages for extensive use of most of these renewable energy sources. Over the last two decades, global electricity production has more than doubled and electricity demand is rising rapidly around the world as economic development spreads to emerging economies. Not only has electricity demand increased significantly, it is the fastest growing end-use of energy. Therefore, technical, economic and environmental benefits of hydroelectric power make it an important contributor to the future world energy mix, particularly in the developing countries.     

An integrated scenario analysis for future zero‐carbon energy system

An integrated scenario analysis methodology has been proposed for zero‐carbon energy system in perspectives of social‐economy, environment and technology. By using the methodology, service demands in all sectors were estimated based on social‐economic data, and then the best technology and energy mixes were obtained to meet the service demands. The methodology was applied to Japan toward zero‐carbon energy system out to the year of 2100, and three different scenarios of nuclear power development are considered in light of the Fukushima accident: (i) no further introduction of nuclear, (ii) fixed portion and (iii) no limit of nuclear. The results show that, zero‐carbon energy scenario can be attained in the year 2100 when electricity will supply 75% of total energy consumption, and three power generation scenarios were proposed, 30% renewable and 70% gas‐carbon capture and storage (CCS) in Scenario 1, respective one‐third nuclear, renewable and gas‐CCS in Scenario 2, and 60% nuclear power, 20% renewable and 10% gas‐CCS in Scenario 3. Finally, Scenario 2 is rated as the most balanced scenario by putting emphasis on the availability of diversified power source, considering the inter‐comparison of the three scenarios from the four aspects of cost, CO₂ emission, risk and diversity. Copyright © 2015 John Wiley & Sons, Ltd.     

Decarbonization synergies from joint planning of electricity and hydrogen production: A Texas case study

Hydrogen (H₂) shows promise as an energy carrier in contributing to emissions reductions from sectors which have been difficult to decarbonize, like industry and transportation. At the same time, flexible H₂ production via electrolysis can also support cost-effective integration of high shares of variable renewable energy (VRE) in the power system. In this work, we develop a least-cost investment planning model to co-optimize investments in electricity and H₂ infrastructure to serve electricity and H₂ demands under various low-carbon scenarios. Applying the model to a case study of Texas in 2050, we find that H₂ is produced in approximately equal amounts from electricity and natural gas under the least-cost expansion plan with a CO₂ price of $30–60/tonne. An increasing CO₂ price favors electrolysis, while increasing H₂ demand favors H₂ production from Steam Methane Reforming (SMR) of natural gas. H₂ production is found to be a cost effective solution to reduce emissions in the electric power system as it provides flexibility otherwise provided by natural gas power plants and enables high shares of VRE with less battery storage. Additionally, the availability of flexible electricity demand via electrolysis makes carbon capture and storage (CCS) deployment for SMR cost-effective at lower CO₂ prices ($90/tonne CO₂) than for power generation ($180/tonne CO₂). The total emissions attributable to H₂ production is found to be dependent on the H₂ demand. The marginal emissions from H₂ production increase with the H₂ demand for CO₂ prices less than $90/tonne CO₂, due to shift in supply from electrolysis to SMR. For a CO₂ price of $60/tonne we estimate the production weighted-average H₂ price to be between $1.30–1.66/kg across three H₂ demand scenarios. These findings indicate the importance of joint planning of electricity and H₂ infrastructure for cost-effective energy system decarbonization.     

Power sector development in India with CO2 emission targets: Effects of regional grid integration and the role of clean technologies

The power sector in India at present comprises of five separate regional electricity grids having practically no integrated operation in between them. This study analyses the utility planning, environmental and economical effects of integrated power sector development at the national level in which the regional electric grids are developed and operated as one integrated system. It also examines the effects of selected CO₂ emission reduction targets in the power sector and the role of renewable power generation technologies in India. The study shows that the integrated development and operation of the power system at the national level would reduce the total cost including fuel cost by 4912 million $, total capacity addition by 2784 MW, while the emission of CO₂, SO₂ and NO_x would be reduced by 231.6 (1.9%), 0.8 (0.9%), 0.4 (1.2%) million tons, respectively, during the planning horizon. Furthermore, the study shows that the expected unserved energy, one of the indices of generation system reliability, would decrease to 26 GWh under integrated national power system from 5158 GWh. As different levels of CO₂ emission reduction targets were imposed, there is a switching of generation from conventional coal plants to gas fired plants, clean coal technologies and nuclear based plants. As a result the capacity expansion cost has increased. It was found that wind power plant is most attractive and economical in the Indian perspective among the renewable options considered (Solar, wind and biomass). Copyright © 2003 John Wiley & Sons, Ltd.     

As a renewable energy hydropower for sustainable development in Turkey

The most important renewable sources are hydropower, biomass, geothermal, solar and wind. Turkey's geographical location has several advantages for extensive use of most of these renewable energy sources. In recently, electricity has demand increased significantly; it is the fastest growing end-use of energy. Therefore, technical, economic and environmental benefits of hydroelectric power make it an important contributor to the future world energy mix. In the world, particularly in the developing countries renewable energy resources appear to be one of the most efficient and effective solutions for sustainable energy development in Turkey. Turkey's geographical location has several advantages for extensive use of most of the renewable energy sources. This paper deals with policies to meet increasing energy and electricity demand for sustainable energy development in Turkey. Turkey has a total gross hydropower potential of 433 GWh/year, but only 125 GWh/year of the total hydroelectric potential of Turkey can be economically used.     

Application,comparative study,and multi-objective optimization of a hydrogen liquefaction system utilizing either ORC or an absorption power cycle

Environmental degradation and global warming are presently two of the most pressing global concerns. According to the (IAE), around 80% of global energy demand has been met by fossil fuels in recent years, resulting in an increase in CO₂ emissions as the primary greenhouse gas. Switching to renewable energy sources and using more energy-efficient energy systems are vital for mitigating environmental challenges and reducing our reliance on fossil fuels, among other things. Hydrogen fuels are primary renewable resources because of their reduced cost and ability to produce net-zero CO₂ emissions. In the present study, a system is designed to generate power and liquid hydrogen from geothermal sources. The generated power by employing either the organic Rankin cycle (ORC) or absorption power cycle (APC) is compared to seek the best cycle performance from power generation standpoint. A comprehensive thermodynamic and economic modeling is carried out for the proposed system. In addition, a parametric study is applied to see which parameters affect the performance of the system. Multi-objective optimization is carried out to find the best operating point of the hydrogen liquefaction energy system. The system demonstrates better performance when APC is applied for power generation. The cost of generated liquid hydrogen by ORC and APC is 3.8 $/kg.LH₂ and 3.6 $/kg.LH₂, respectively. Furthermore, 0.014 $/kWh of electricity cost is reached by ORC compared to 0.012 $/kWh of APC. Parametric analysis shows that the higher the temperature and flow rate of the brine of geothermal fluid, the higher the efficiency and the lower cost. Finally, the multi-objective optimization pinpoints that the system's efficiency and unit product cost at the optimal ORC-based design is 33.85% and 0.0121 $/kWh. In comparison, the APC demonstrates better performance by 34.5% and 0.011 $/kWh.     

Economic accounting and high-tech strategy for sustainable production: A case study of methanol production from CO2 hydrogenation

The global proposal of ‘carbon neutrality’ puts forward higher innovation demand for the cleaner energy production. The potential for employing “green” methanol produced from hydrogen obtained by water electrolysis and collected CO₂ from a gas-fired power station is examined in this study.The consumption of electricity for renewable methanol production is 1.045 times as much as that for traditional methanol production, the traditional method consumes 2.5 times as much thermal energy as the renewable methanol process. In addition, the total direct and indirect CO₂ emissions from renewable methanol production are almost one-third of the emissions from the traditional method. The total cost of setting up the units of a renewable and a traditional methanol production plant with an annual capacity of 100,000 tons is $50.1 million and $46.806 million in this study case, respectively. If the methanol price hits $310 per ton, renewable methanol production will be highly economically viable. But if electricity and gas prices rise or CO2 emission tax is imposed, renewable and conventional methanol production plants will lose their economic feasibility. Therefore, in order to deal with this risk, the establishment of special high-tech parks is of great significance to reduce costs and stabilize the sustainable development of relevant industries.     

Sectoral CO2 emission reductions in Turkey: Preparing for DOHA 2020

In this study, CO₂ emissions in different sectors in Turkey were examined in order to serve as a foundation for planning future reduction of greenhouse gas emissions. These reductions are being planned in accordance with the Kyoto Protocol, of which Turkey is a signatory, and which was re-examined by the Doha Climate Change Conference in 2009. For this purpose, variation of the total factor efficiencies of CO₂ emissions per capita for many developed and developing countries including Turkey (35 countries in total) were examined by data envelopment analysis and Malmquist Index approaches. It was aimed to determine the sectors in Turkey that should be the primary foci for reductions of CO₂ emissions and which actions might be taken before Doha 2020 oriented towards reductions in CO₂ emissions in these sectors. Meanwhile, current regulations and perspectives for greenhouse gas plans developed within the scope of Vision 2023 were discussed.     

Exploiting the oil–GDP effect to support renewables deployment

The empirical evidence from a growing body of academic literature clearly suggests that oil price increases and volatility dampen macroeconomic growth by raising inflation and unemployment and by depressing the value of financial and other assets. Surprisingly, this issue seems to have received little attention from energy policy makers.In percentage terms, the oil–GDP effect is relatively small, producing losses in the order of 0.5% of GDP for a 10% oil price increase. In absolute terms however, even a 10% oil price rise—oil has risen at least 50% in the last year alone—produces GDP losses that, could they have been averted, would significantly offset the cost of increased RE deployment. This paper draws on the empirical oil–GDP literature, which we summarize, to show that (i) by displacing gas and oil, renewable energy investments can help nations avoid costly macroeconomic losses produced by the oil–GDP effect and, (ii) that these avoided losses represent a significant external macroeconomic benefit of such investments.We show that a 10% increase in RE share avoids GDP losses in the range of $29–$53 billion in the US and the EU ($49–$90 billion for OECD). These avoided losses offset one-fifth of the RE investment needs projected by the EREC and half the OECD investment projected by a G-8 Task Force. For the US, the figures further suggest that each additional kW of renewables, on average, avoids $250–$450 in GDP losses, a figure that varies across technologies as a function of annual capacity factors. We approximate that the offset is worth $200/kW for wind and solar and $800/kW for geothermal and biomass. While we focus only on renewables, the GDP offset will apply in some measure to other non-fossil technologies including energy efficiency, DSM and nuclear. The societal valuation of non-fossil alternatives must reflect these avoided GDP losses, whose benefit is not fully captured by private investors. This said, we fully recognize that wealth created in this manner does not directly form a pool of public funds that is easily earmarked for renewables support.Finally, the oil–GDP relationship has important implications for correctly estimating direct electricity generating cost for conventional and renewable alternatives and for developing more useful energy security and diversity concepts. We also address these issues.     

Global warming and environmental benefits of hydroelectric for sustainable energy in Turkey

Over the last two decades; technical, economic and environmental benefits of hydroelectric power make it an important contributor to the future world energy mix, particularly in the developing countries. Turkey has a total gross hydropower potential of 433 GWh/yr, but only 125 GWh/yr of the total hydroelectric potential of Turkey can be economically used. By the commissioning of new hydropower plants, which are under construction, 36% of the economically usable potential of the country would be tapped. Turkey's total economically usable small hydropower potential is 3.75 GWh/yr. It is expected that the demand for electric energy in Turkey will be about 580 billion kWh by the year 2020. Turkey is heavily dependent on expensive imported energy sources that place a big burden on the economy and air pollution is becoming a great environmental concern in the country. In this regard, renewable energy resources appear to be the one of the most efficient and effective solutions for clean and sustainable energy development in Turkey. Environmentally friendly energy development has enormous implications for developing countries as major emitters due to their rapid economic and population growth. With some possible options, the paper concludes that the reduction of emissions can only be achieved when policies are supportive and well targeted, standards and incentives are realistic and flexible, and the public is actively responsive to environmental degradation. Turkey's high rate of energy-related carbon emissions growth is expected to accelerate, with emissions climbing from 57 million tons in 2000 to almost 210 million tons in 2020. Carbon intensity in Turkey is higher than the western developed nation average. In this regard, renewable energy resources appear to be one of the most efficient and effective solutions for clean and sustainable energy development in Turkey. This paper deals with Turkey's renewables energy sources for sustainable environment.     

Achieving California's 80% greenhouse gas reduction target in 2050: Technology,policy and scenario analysis using CA-TIMES energy economic systems model

The CA-TIMES optimization model of the California Energy System (v1.5) is used to understand how California can meet the 2050 targets for greenhouse gas (GHG) emissions (80% below 1990 levels). This model represents energy supply and demand sectors in California and simulates the technology and resource requirements needed to meet projected energy service demands. The model includes assumptions on policy constraints, as well as technology and resource costs and availability. Multiple scenarios are developed to analyze the changes and investments in low-carbon electricity generation, alternative fuels and advanced vehicles in transportation, resource utilization, and efficiency improvements across many sectors. Results show that major energy transformations are needed but that achieving the 80% reduction goal for California is possible at reasonable average carbon reduction cost ($9 to $124/tonne CO₂e at 4% discount rate) relative to a baseline scenario. Availability of low-carbon resources such as nuclear power, carbon capture and sequestration (CCS), biofuels, wind and solar generation, and demand reduction all serve to lower the mitigation costs, but CCS is a key technology for achieving the lowest mitigation costs.     

Emissions reduction scenarios in the Argentinean Energy Sector

In this paper the LEAP, TIAM-ECN, and GCAM models were applied to evaluate the impact of a variety of climate change control policies (including carbon pricing and emission constraints relative to a base year) on primary energy consumption, final energy consumption, electricity sector development, and CO₂ emission savings of the energy sector in Argentina over the 2010–2050 period. The LEAP model results indicate that if Argentina fully implements the most feasible mitigation measures currently under consideration by official bodies and key academic institutions on energy supply and demand, such as the ProBiomass program, a cumulative incremental economic cost of 22.8 billion US$(2005) to 2050 is expected, resulting in a 16% reduction in GHG emissions compared to a business-as-usual scenario. These measures also bring economic co-benefits, such as a reduction of energy imports improving the balance of trade. A Low CO₂ price scenario in LEAP results in the replacement of coal by nuclear and wind energy in electricity expansion. A High CO₂ price leverages additional investments in hydropower. By way of cross-model comparison with the TIAM-ECN and GCAM global integrated assessment models, significant variation in projected emissions reductions in the carbon price scenarios was observed, which illustrates the inherent uncertainties associated with such long-term projections. These models predict approximately 37% and 94% reductions under the High CO₂ price scenario, respectively. By comparison, the LEAP model, using an approach based on the assessment of a limited set of mitigation options, predicts an 11.3% reduction. The main reasons for this difference include varying assumptions about technology cost and availability, CO₂ storage capacity, and the ability to import bioenergy. An emission cap scenario (2050 emissions 20% lower than 2010 emissions) is feasible by including such measures as CCS and Bio CCS, but at a significant cost. In terms of technology pathways, the models agree that fossil fuels, in particular natural gas, will remain an important part of the electricity mix in the core baseline scenario. According to the models there is agreement that the introduction of a carbon price will lead to a decline in absolute and relative shares of aggregate fossil fuel generation. However, predictions vary as to the extent to which coal, nuclear and renewable energy play a role.     

Potential of renewable energy in electrical energy production and sustainable energy development of Turkey: Performance and policies

Generating electricity, from renewable energy sources has become a high priority in the energy policy strategies at a national level as well as on a global scale. Although Turkey has many energy resources only coal and hydropower are significant at present, and as demand had risen, it has been necessary to import fuels to meet the total energy demand. The fossil resources, both indigenous and imported, have become expensive and also have undesirably high emissions. Turkey has an extensive shoreline and mountains and is rich in renewable energy potential. The share of renewables on total electricity generation is 35% while that of thermal power is 65% for the year 2010. Turkey is one of those countries that are considered rich and abundant in renewable energy resources.Turkey is facing serious challenges in satisfying its growing energy demand. To fuel a rapidly growing economy, the country’s electricity consumption is increasing by an average of 8–9% every year, and significant investments are needed in generation, transmission and distribution facilities to balance the power system’s supply and demand. With very limited oil and gas reserves, Turkey is increasingly turning to renewable energy sources as a means to improve its energy security and curb dependence on imported gas from Russia and Iran. This paper investigates the potential of renewable energy resources in Turkey at present and the magnitude of their present and future contributions to the national energy consumption. Energy politics are also considered.     

Transient simulation and techno-economic assessment of a near-zero energy building using a hydrogen storage system and different backup fuels

Proposing a cost-effective off-grid Hybrid Renewable Energy System (HRES) with hydrogen energy storage with a minimum CO2 emission is the main objective of the current study. The electricity demand of an office building is considered to be supplied by Photovoltaic Panels and wind turbines. The office building, modeled in Energy Plus and Open studio, has annual electricity consumption of 500 MWh electricity. 48.9% of the required electricity can be generated via renewable resources. Considering a system without energy storage, the remaining amount of electricity is generated from diesel generators. Hence, for reducing CO2 emission and fuel costs, a hydrogen energy storage system (ESS) is integrated into the system. Hydrogen ESS is responsible for supplying 38.6% of the demand electricity, which means that it can increase the energy supplying ability of the system from 48.9% to 87.5%. In addition to analyzing the application of the hydrogen storage system, the effect of four different kinds of fuel is considered as well. effects of Natural gas, Diesel, Propane, and LPG on the system's application are investigated in this study. Results indicate that natural gas emits less amount of CO2 compared to other fuels and also has a fuel cost of 3054 $/year, while hydrogen ESS is available. For the renewable system without ESS, the fuel cost rises to 10,266 $/year. However, liquid gas, Propane, and LPG have better performance in terms of CO2 emission and fuel cost, respectively.     

Biomass and bio-energy utilisation in a farm-based combined heat and power facility

Five different renewable energy technologies located at an agricultural and environmental research centre in Northern Ireland, were monitored to assess the cost, performance and efficiency in real-time operation of solar and bio-energy produced from crops and farm wastes utilised for energy generation in industrial grade equipment. Monitoring was conducted over a six year period, with power units running simultaneously or intermittently according to demand from the local district heating system. The purpose of the work was to investigate fossil fuel (oil) displacement, carbon dioxide emission (CO₂e) reductions, financial and environmental sustainability of these technologies in a farm based scenario. Between 2009 and 2014, total heat output from the centre was 7.75 GWh with contributions of 47.2%, 17.1%, 9.8% and 13.5% from the biomass, biogas, multi-fuel boiler and biogas CHP unit respectively. Solar thermal produced 0.49% and the back-up oil boiler 11.9%. Total electrical output was 572.6 MWh with 95.2% generated from biogas CHP and 4.8% from the solar PV system. Fossil fuel and average CO₂e reductions ranged from 20.1% to 54.1% and 23.3–55.7% respectively, reductions that combined with financial savings to present a viable and sustainable renewable energy system.     

Current situation and development prospects of metallurgical by-product gas utilization in China's steel industry

China's annual metallurgical by-product gas production exceeds 1400 billion Nm³, the calorific equivalent of ∼266 million tonnes of coal. The widely-studied blast furnace gas used in hydrogen-enriched carbonic oxide recycling oxygenate furnaces ensures carbon-reduction. Converter gas contains abundant heat resources, equivalent to ∼6.5 million tonnes of coal. Using high-temperature by-product gas online reforming methods to convert thermal energy into chemical energy and combining it with power generation and other industries imparts physical heat recovery exceeding 60%. China's annual coke oven gas (COG) production could support more than 100 million tonnes of direct reduced iron production, thus reducing CO₂ emissions by more than 150 million tonnes (nearly 10% of China's steel industry CO₂ emissions). We summarise the characteristics, availability, and steel-chemical co-production utilisation of three by-product gases, and discuss the application of COG in direct reduced iron production and development of metallurgical by-product gas utilisation for carbon reduction in China.     

Transitioning electricity systems: The environmental benefits and economic cost of repurposing surplus electricity in non-conventional end users

A power grid with a lower global warming impact has the potential to extend its benefits to energy systems that conventionally do not utilize electricity as their primary energy source. This study presents the case of Ontario where the role of complementing policies in transitioning electricity systems is assessed. The policy cost to incentivize surplus low emission electricity via an established mechanism for the transportation sector has been estimated (Electric and Hydrogen Vehicle Incentive Program). It is estimated that the 9056 (4760 battery and 4296 plug-in hybrid) electric vehicles that qualified for incentives from the provincial government at the end of 2016 vehicles cost $732.5-$883.9 to reduce a tonne of CO_2,e emissions over an eight year lifetime. This is then compared with the potential cost incurred by two power to gas energy hubs that utilize clean surplus electricity from the province to offset emissions within the natural gas sector. The use of hydrogen-enriched natural gas and synthetic natural gas (SNG) offsets emissions at $87.8 and $228.7 per tonne of CO_2,e in the natural gas sector. This analysis highlights the potential future costs for incentivizing new clean technologies such as electric vehicles and power to gas energy hubs in jurisdictions with a transitioning electricity system.     

Cost‐effectiveness analysis of energy efficiency measures in the Swiss chemical and pharmaceutical industry

Energy efficiency improvement is an effective way of reducing energy demand and CO₂ emissions. Although the overall final energy savings potential in chemical industry has been estimated in a few countries, energy efficiency potentials by concrete measures applicable in the sector have been scarcely explored and their associated costs are hardly analyzed. In Switzerland, the production of chemicals and pharmaceuticals exceeds all other industrial sectors in terms of energy use and CO₂ emissions, and it accounted for 22% of the total industry's overall final energy demand and 25% of the CO₂ emissions related to non‐renewable energy sources in 2016. In this study, the economic potentials for energy efficiency improvement and CO₂ emissions reduction in the Swiss chemical and pharmaceutical industry are investigated in the form of energy efficiency cost curves. The economic potential for final energy savings and CO₂ abatement based on energy‐relevant investments is estimated at 15% and 22% of the sector's final energy use and fossil fuel‐related CO₂ emissions in 2016, respectively. Measures related to process heat integration are expected to play a key role for final energy savings. The economic electricity savings potential by improving motor systems is estimated at 15% of the electricity demand by these systems in 2016. The size of economic potential of energy efficiency improvement across the sector decreases from 15% to 11% for 0.5 times lower final energy prices while the size increases insignificantly for 1.5 times higher final energy prices. The additional power generation potential based on Combined Heat and Power plants is estimated at 14 MW for 2016. This study is a contribution to the so far limited international literature on economic energy efficiency measures applicable in this heterogeneous sector and can support policy development. The results for specific costs of energy efficiency measures can also be adapted to other parts of the world by making suitable adjustments which in return may provide useful insights for decision makers to invest in economically viable clean energy solutions.     

Hydropower in Turkey for a clean and sustainable energy future

Over the last two decades, global electricity production has more than doubled and electricity demand is rising rapidly around the world as economic development spreads to emerging economies. Not only has electricity demand increased significantly, it is the fastest growing end-use of energy. Therefore, technical, economic and environmental benefits of hydroelectric power make it an important contributor to the future world energy mix, particularly in the developing countries. This paper deals with policies to meet increasing energy and electricity demand for sustainable energy development in Turkey. Turkey has a total gross hydropower potential of 433 GWh/year, but only 125 GWh/year of the total hydroelectric potential of Turkey can be economically used. By the commissioning of new hydropower plants, which are under construction, 36% of the economically usable potential of the country would be tapped. Turkey's total economically usable small hydropower potential is 3.75 GWh/year.     

Investment screening model for spatial deployment of power-to-gas plants on a national scale – A Danish case

When transitioning to a 100% renewable energy system storing electricity becomes a focal point, as the resource flexibility is lost and the design of the energy system needs to provide flexibility and balancing options to integrate intermittent renewable resources. Using technologies such as power-to-gas offers an opportunity to store electricity in chemical form, which can be used as a long-term storage option. This paper develops a spatial modelling method by using a GIS tool to investigate potential generation sites for power-to-gas plants. The method determines the location of the plants by carbon source potential, proximity of the grid, costs of grid transmission and investment costs of the technology itself. By combining these types of data, it is possible to identify the investment costs of the power-to-gas plants. The method focuses on two paths: biogas upgrade and CO₂ methanation. The method is applied to a specific case by investigating the power-to-gas potential in Denmark. The potential and spatial deployment is found by examining the investment costs of plants with an annual gas production of 60 GWh. The findings of the analysis indicate that the biogas upgrade path is the cheapest one of the two, at the present cost level, but due to the relatively small number of biogas plants in Denmark, the chosen plant size is limited to around 55 plants. CO₂ methanation is a more costly path, but it has a larger potential of around 800 plants. As the analysis is based on the current sources for biogas and CO₂, it is important to emphasise that the potential for CO₂ methanation plants can be expected to diminish in the future as more renewable energy is introduced, lowering the need for thermal energy producers, while biogas production could see an increase. Nevertheless, the analysis of a specific case shows that the method gives a good indication of the extent of the power-to-gas resources by using a novel approach to the matter. The method can be applied in other countries as well, giving it a wide appeal.