ENERGY Energy is the capacity of a system to do work Energy is always conserved but … … can be transformed from one form to another Energy, E (unit: 1 joule = 1 J or N m) Power, P = dE / dt (unit: 1 watt = 1 J s -1 or 1 W) (where time, t / s) 1 J is about the energy required to raise 100 g (e. g., a mobile phone) vertically 1 m against Earth’s gravity at sea-level (g =9.81 m s -2 ) I W is the power required to do this in 1 s Many different kinds of energy: kinetic, potential, mass (chemical, electrical, magnetic, gravitational, thermal, nuclear,...) Here we are interested in energy used directly or indirectly by people for heat and power, and related key issues.

6.9 billion now World population net current growth rate about 9,100 people per hour

Economic growth

Increased energy demand 1 quad = 1 quadrillion Btu = Btu =1.055  J = EJ 528 EJ world energy consumption in 2009 ↔ 16.7 TW globally or 2.5 kW per person on average

Peak oil … and coal, gas, uranium

Anthropogenic climate change Intergovernmental Panel on Climate Change, IPCC (2007)

enlightened Energy Policy affordable energy on demand

UK Energy Policy largely set by Energy White Paper (2007) and The UK Low Carbon Transition Plan (2009) UK Energy Policy

Energy Conversion Energy cannot be created or destroyed (first law of thermodynamics). However energy in one form E x (heat, work, chemical, mass) may be converted into energy of another form E y via suitable technology.

Contributions of Process Industries to Global Environmental Problems Many global problems arise from energy use, and resulting depletion of raw materials and increasing emissions. EnergyRaw Materials Main product(s) Co-products (waste) Process we are interested in the case where the product is energy (in a different form than input)

World primary energy supply Sectors Industry Domestic Transport Services

Scope Energy used in sectors: industry, transport, domestic, services (agriculture, hospitals, …) Consider main energy conversion technologies.

Fossil Fuels coal, oil, gas power generation and transport SO x, NO x, VOC, CO, waste heat CO 2 efficient land use non-renewable sensitive to political instability?

Nuclear fission, fusion fuel reprocessing de-commissioning short/long term radiation hazard nuclear arms no direct CO2 emissions terrorism non-renewable

Biomass broadly CO2 neutral requires large land areas significant water usage competes with food production has niche as by-product of waste disposal

Wind Power variable power available can be land or off- shore moderate area use intermediate technology planning?

Water Power hydro, wave, tides, currents clean reputation low running costs can be environmentally disruptive can destroy land can arise from political oppression some real technical challenges

Solar Power photovoltaic, passive solar heating, solar concentrators fairly efficient land use intermittent depends on latitude some cost issues with PV

Geothermal Energy hot water from underground reservoirs or via cold water pumped from surface turbine power or direct heating depends on local geology green though undeveloped technology

World Energy

UK Energy Digest of United Kingdom Energy Statistics 2010 (“Dukes”) UK Energy in Brief 2010

Energy Forecast (UK) central issues are energy sustainability & security remains largely fossil based throughout 21st century? off-shore wind and wave power? next generation of nuclear power? hydrogen economy?? effects of global warming may be discovered the hard way