Powered by Rock Dr Liam Herringshaw Earth's Energy Systems

Week 8: Reviewing The Options

Why Bother? “The UK is committed to reducing its greenhouse gas emissions by at least 80% by 2050, relative to 1990 levels”

A Quick Recap

1. Coal FOR Cheap Available Employment Base-level power Known technology Existing infrastructure Inert material CCS AGAINST Climate change Pollutants Import dependence Opencast impact Subsidence Easy resources exhausted CCS uncertainty

2a/b. Oil & Gas FOR Availability Revenue generator Existing infrastructure UK energy security Cleanliness of gas CCS AGAINST Spills, pollution, emissions Geopolitics Import dependence Over-reliance

3. Nuclear FOR Very low CO2 impact Available technology Baseload supply Large capacity Area vs Mwh Thorium potential AGAINST Danger Accidents Terrorism Waste disposal Long-term impacts Construction costs

4. Geothermal FOR Heat supply Local potential Dependency Low visual impact No external energy source required AGAINST Uneven distribution UK potential? Construction cost Low production? Fracking Radon release

5. Hydro FOR Proven renewable Long-term supply Security Low emissions UK tidal potential AGAINST Cost of development Environmental impact Raw materials Induced seismicity Unproven tidal/wave

6a. Wind FOR Clean, emission-free Aesthetics Easily built/removed Known technology Unlimited resource Employment AGAINST Intermittency Aesthetics Wildlife impacts Storage? Non-local construction Lifespan

6b. Solar FOR Clean, emission-free Local usage Water heating Speed of construction AGAINST Inefficiency Non-local mineral sources Uneven distribution Cleaning!

Original rankings In week 1, how did you rank them? – Coal, oil, gas, nuclear, geothermal, hydro, wind, solar

Strengths & Weaknesses COAL CHIEF STRENGTH Abundance + cheapness CHIEF WEAKNESS Environmental impacts

Strengths & Weaknesses OIL & GAS CHIEF STRENGTH Abundance + cheapness CHIEF WEAKNESS Environmental impacts

Strengths & Weaknesses NUCLEAR CHIEF STRENGTH Reliability CHIEF WEAKNESS Radioactive risks (perceived or real)

German nuclear challenge Having abandoned nuclear power, and stopped solar support, German power increasingly coal-dependent

Renewable sustainability Evans et al. (2009) compared: Hydroelectric power Wind power Photovoltaic solar power Geothermal power + Coal + Gas

Evans et al. (2009) Price of generated electricity; Full life-cycle GHG emissions; Source availability; Conversion efficiency; Land requirements; Water consumption; Social impacts

Findings Efficiency of electricity generation: Photovoltaic 4–22% Wind 24–54% Hydro >90% Geothermal 10–20% Coal 32–45% Gas 45–53%

Findings Water consumption in kg per kWh of electricity generation: Photovoltaic 10 Wind 1 Hydro 36 Geothermal 12–300 Coal 78 Gas 78

Findings Greenhouse Gas Emissions

Findings

Conclusion Variabilities due to technology and geography But: Wind power most sustainable, then hydroelectric, PV solar, geothermal

Raw materials Vidal et al. - Nature Geoscience (2013)

Some data to digest Pacca & Horvath (2002):

Some data to digest Pihl et al (2012) compared 2 types of CSP – tower vs trough Materials required: Aluminium (Metal), Cement, Chromium, Copper, Aluminium (Elemental), Fibreglass, Foam glass, Glass, Iron, KNO3, Lime, Limestone, Magnesium, Manganese, Molybdenum, NaNO3, Nickel, Niobium, Oil, Polypropylene, Rock, Rock wool, Sand, Silicon sand, Silver, Soda ash, Steel, Titanium, Vanadium, Zinc.

The UK Energy Mix

The Recent Past

The Future?

Predictability? IEA World Energy Outlook “hides the real potential of renewables”

Your UK preferences Week 1 rankings: – Coal, oil, gas, nuclear, geothermal, hydro, wind, solar Have you changed your mind at all? Why?

My UK preferences Baseload: Gas with CCS + Nuclear (+ Tidal) Additional grid: Wind + Hydroelectric Local-scale: Solar + Geothermal Reduced usage Improved efficiency

A More Informed Approach? Try the UK 2050 Calculator: 2050-calculator-tool.decc.gov.uk/