### Energy resources

#### Indicators:

Remaining fossil fuel resources Primary energy carrier price Cumulative production | Renewable energy resources Energy production from renewable resources Share of renewables in total primary energy use

The indicators included in "energy resources" show the natural resource aspect of the energy system. For the fossil fuel resources, relevant indicators are the geographic distribution of the resources at any moment in time, their quality as indicated by the price of the resources produced at that moment in time, and the cumulative productuion as a measure of depletion. For the renewable resources (biomass-derived fuels, hydropower and solar/wind etc.) their use is indicated as fraction of the estimated potential and as the size of the extracted flow.

| #### Remaining fossil fuel resources
| unit: PJ (Petajoule) dimension: region, primary energy carrier

The remaining resources show for all regions the remaining fossil fuel resource in any year within the period 1970 to 2100. Resources refer here to 'ultimately recoverable resources' as of 1971. Estimates are based on literature combined with the 1971-1995 resource consumption. For each fuel and each region, a long-term cost supply curve has been estimated which indicates the increase in capital-output ratio as a function of the fraction of resources remaining. For all energy carriers, the ultimately recoverable resources shown here are very large due to the inclusion of non-conventional occurrence such as tar sands and methane hydrates.

| #### Primary energy carrier price
| unit: US$ (1995)/GJ (1995-US Dollars per Gigajoule) dimension: region, primary energy carrier

Primary energy carrier prices in each region are shown. They are calculated from regional fuel production costs and costs of imported fuels. The regional fuel production costs are determined by the long-run supply cost curve and the depletion and learning-by-doing parameters. The costs of imported fuels depend on the regional production costs, the transport distances and unit costs, and a simple supply-demand mechanism (see net fuel trade).

| #### Cumulative production
| unit: 1000 PJ (thousand Petajoule) dimension: region, primary energy carrier

Cumulative production shows for all regions the cumulative energy production for fossil fuel resources, starting in 1971. Cumulative production is one of the cost determinants for two reasons. First, the capital-output ratio is assumed to rise non-linearly with the ratio of cumulative production and initial resource. Secondly, innovations in fossil fuel exploration and exploitation are driven by production through the progress ratio which indicates how much the capital-output ration will decline per doubling of cumulative production. Cumulative production of the fossil fuels also gives an indication of the cumulative carbon emissions.

| #### Renewable resource utilization
| unit: none (fraction of potential renewable resources used) dimension: region, primary energy carrier

A basic assumption in the TIMER model is that the costs of renewable energy will increase the closer it approaches some exogenously estimated potential. Obviously, this potential is a rather arbitrary parameter - as it depends on assumptions about land availability, accessability to resources, technological development etc. The indicator here shows the fraction of the renewable energy resource potential, which is actually used, for each region. For modern biofuels, the potential (maximum) production per region is based on land availability and productivity as calculated by the land-use model of IMAGE 2.4. For hydropower, solar and wind the potential per region has been based on various literature sources.

| #### Energy production from renewable resources
| unit: 1000 PJ (thousand Petajoule) dimension: region, primary energy carrier

Energy production shows the total production for several types of renewable energy. Produced biofuels can be traded among all regions, depending on demand and regional production costs. Hydropower and solar/wind based electricity can be traded as part of total electricity trade, but these flows are normally relatively small.

| #### Share of renewables in total primary energy use
| unit: none (fraction) dimension: region, primary energy carrier

Share of renewables in total primary energy use shows the fraction of commercial biofuels, hydropower and solar/wind based electricity in the total primary energy use.