22 Jul Renewable Energy in IB ESS: Benefits, Limits and Calculations
Renewable energy comes from sources replenished by natural processes. Solar, wind, hydropower, geothermal energy and biomass are major examples. Availability and the way a resource is used still matter: renewable does not automatically mean unlimited supply at any time or no environmental harm.
Compare benefits and limitations
Ask what the technology replaces, where it operates and which impacts are included in the comparison. Distinguish emissions during operation from those associated with materials, construction, transport and disposal. State the boundary of your evidence rather than calling every renewable technology “zero emission”.
For solar and wind, discuss variable generation and the need to match electricity supply with demand. Consider storage, transmission and demand management where relevant. For hydropower, consider effects on river systems and communities. The strongest choice depends on the location and the objectives used to compare options.
Capacity is not electricity generated
Illustrative calculation: a 2 MW installation producing 4,380 MWh in a non-leap year has a capacity factor of 4,380 ÷ (2 × 8,760) = 0.25, or 25%. This is the ratio of actual generation to continuous operation at rated output; it is not the technology’s energy-conversion efficiency. The numbers are a practice example, not measured performance of a named project.
Biomass needs careful treatment
Burning biomass releases carbon dioxide and can produce air pollutants. Regrowth and sustainable harvesting matter. If wood is removed faster than it grows back, the use can cause deforestation. Do not assume that the renewable label alone establishes a beneficial carbon balance.
Use statistics responsibly
Check whether a statistic describes electricity generation, total energy consumption or installed capacity. Include country, year, units and the primary source. These measures are not interchangeable. Check current policy before presenting a tax credit or financial incentive as available.
Build a balanced comparison table
Compare options under the same headings: energy service provided, local resource availability, reliability, lifecycle impacts and affected stakeholders. Use the same units and time period when figures are available. Explain which criterion matters most in your chosen context before reaching a judgement.
Original comparison exercise
Choose two energy options for a school. Identify the information needed to compare reliability, local impacts and costs. Explain a trade-off rather than declaring a universal winner. No results or grades are invented for this exercise.
Primary sources: EIA renewable energy overview and EIA on biomass impacts.
Practise with individual ESS support
In Marija’s online IB ESS SL and HL lessons, you can work on concepts, data interpretation and clear explanations. Request a free 20-minute trial lesson to discuss your priorities. For IA work, the investigation and submitted writing remain your own.
Official reference: IB ESS guide, first assessment 2026. Updated 19 October 2026.
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