energy part 2

The potential for sustainable energy supply & consumption

the environmental value of an energy resource is judged by its sustainability, so for energy production to be sustainable, it musn't deplete any resources or cause any long term environmental damage.

BIOMASS (aka biofuel, it's living matter that is converted into energy)

Biomass in Mali:

• 90% of their energy mix is fuelwood because it's cheap, accessible, have/had large reserves and as an LEDC they cannot afford coal and oil imports (also landlocked so even more expensive).
• 60% of the population is rural, so cannot afford other sources and need PRIMARY ENERGY resources because they hace had no access to electricity
• Disadvantages: unsustainable as it emits pollutants & is a flow resource; desertification; health problems (back ache) for women and children collecting fuelwood
• Alternatives: make biofuel out of Jatropha - oil which is in seeds of a plant

When oil prices rose in 1973, Brazil decided to reduce their reliance on it by producing ethanol to use as a fuel for cars, from their sugar cane resources.

Flex cars have been using ethanol for the last 30 years. There's been a rapid growth of Flex cars in Brazil, which run on petrol and ethanol. Over 80% of car sales are now Flex cars.

Advantages:

• provides employment
• supports agriculture
• boosts Brazil's economy from Flex car sales
• Flex engines are mor environmentally friendly than petrol engines
• Motorists have the option between fuels - but ethanols cheaper
• Reduction in expensive oil imports, so is more self-sufficient

Disadvantages:

• Burning of sugar cane releases carbon dioxide
• Deforestation as rainforests destroyed to create space for more sugar cane fields

Sustainability: Brazil has large sugar cane resources so no resource depletion, but the use of biofuels has both positive and negative environmental impacts

Advantages of biofuels

• more renewable and sustainable than fossil fuels
• could displace oil for use in transport as they can be used with existing vehicles (also oil prices keep rising)
• different types of biofuels grown worldwide, so unlike fossil fuels global trade wouldn't just be controlled by a certain number of countries
• in theory biofuels are carbon-neutral as they absorb carbon dioxide when growing but release it when burnt

Increasing demand could lead to mass deforestation. Pollutants would be released and so offset biofuel being carbon-neutral. Trees are a carbon store and when cut they release this into the atmospher.

Farmland traditionally used for food crops and livestock is instead being used to grow crops for biofuelds, leading to food shotages in some LEDC's

PV cells in the UK:

It's too cloudy in the UK for solar farms to be effective, however PV cells (solar panels on the roof) are still possible to convert light energy into electricity.

Advantages:

• don't need direct sunlight - can still generate some electricity on a cloudy day
• households can applu for a govt loan to help with installation costs
• if households produce more than necessary, this can be sold to the National Grid
• Some companies will instead PV cells for free, in exchange for the surplus of generate electricity
• Households/businesses get a "feed in tariff" - a payment from the govt for generating clean energy

Disadvantages:

• Expensive to install and solar energy only provides about 1% of the UK's energy mix
• Carbon dioxide is released during manufacturing

British Gas have fitted 156 solar panels onto the roof of one of Greenhead's buildings as part of their "Solar for Schools" scheme: supplying 1000's of schools with free solar systems.

British Gas get the surplus of electricity which they sell back to the National Grid, and then reinvest in more schools. But Greenhead uses what they need of the electricity generated to power the college, surplus is mainly generated during holidays.

Greenhead College also to be more efficient:

• Have light sensors which switch lights off when no one is moving
• Have controlled air conditioning which turns off when the correct temp is reached
• Have double glazed windows to insulate the building, thus reducing the need for heating
• Have timed central heating

there's huge potential in Mali with 5/6 hours of sunlight per day, but only 0.1% of this LEDC's energy mix is renewable.

However there are small-scale solar power projects going on, like the 30 Mali schools being fitted with solar panels, funded by the MFC (Mali Folke Centre - a partner of Christian Aid). And solar cookers have also been introduced in certain areas.

These are sustainable and appropriate technologies because:

• Mali is less dependent on fuelwood, which decreases CO2 emissions
• the locals have been shown how to maintain the panels and cookers themselves
• The solar cookers will benefit the people also because they're no loger breathing in smoke from burning fuelwood, so less respiratory problems
• They're not spending the day collecting firewood - they can leave the food to cook and go do other things

Small-scale wind energy project in Kirklees

In 2006, 2 turbines were installed (Cost £100,000) on top of the Civic Centre in Huddersfield, as part of Kirkless Council's aim of raising awareness on global warming and renewable energy. they were the 1st in the UK on a local authority building. The turbines didn't generate a surplus of energy to sell toe the National Grid. Also, 1 broke and was too costly to repair. However, the turbin suppliers, Proven Energy, replaced both turbines free of charge and relocated them to a better site. They should now generate more energy so the council can pay of servicing costs and actually make an annual profit.

Advantages:

• No greenhouse gases emitted once set up & renewable resource
• Turbines can be dismantled when wanted to restore the landscape
• Low running cost
• Land beneat the turbines can be used for farming
• Govt grants will subsidise the cost of production
• Can be used on projects of different scales

Disadvantages:

• Turbines can harm/kill birds
• Noise pollution
• Large number of turbines needed to produce a significant amount which requires large spaces
• CO2 released during production and installation
• The windiest, most suitable sites tend to be areas of natural beauty, so can be an eyesore
• Only have a max lifespan of 50 years and wind farms hurt property prices nearby
• Unreliable form of energy because it's not always windy - 40% of real capacity at its best

The movement of tides is used to create power. River estuaries (the tidal mouth of a river - where the tide meets the stream) with large tidal range have tidal barrages built across them to generate electricity. As the tide flows in and out, the water passes through gates in the barrage, turning turbines that generate electricity.

The proposed severn tide barrage, UK:

In 2007, plans were first proposed to build a tidal barrage across the Severn estuary. but in october 2010 the proposal was rejected, and there is still no severn tidal barrage built. however, this case study still illustrates the arguments for and against tidal barrages and is applicable to others in the UK like Solway Firth and Morecambe Bay

• Renewable
• Tidal's more reliable than solar and wind energy
• The Severn Barrage could have produced as much energy as 5 power stations
• Would reduce erosion rates behind the barrage, benefiting the estuary
• No greenhouse gases once set up
• The Severn Estuary has the 2nd highest tidal range in the world
• It could have doubled the current renewable energy amount in the UK's energy mix

Disadvantages

• Turbines could kill aquatic animals
• Extremely high construction costs
• Releases CO2 during construction
• Eyesore

Other drawbacks of tidal in general: Tidal could only ever produce at absolute maximum, 20% of global demand

• isnt possible in most areas of seas as it needs speed currents found only in shallow seas (20 suitable locations worldwide)
• the presence of barrages themselves alters the currents so energy can't be efficiently extracted

Orkney Islands and Island of Islay in Scotland:

Wave power is still a very undeveloped renewable energy resource, so only small scale wave energy schemes are in operation, testing different wave energy models.

Hopes with projects:

• Orkney to become worlds biggest supplier of wave energy
• Hope to have 100's of turbines
• Power 1000's of homes - could supply 1/5 of UK's energy if there's a sufficient amount of turbines

Issues:

• Potential threat of underwater noise pollution, which would distrupt marine life
• Restricted sea areas would damage fish industry
• Eyesore

Advantages:

• Renewable
• No CO2 emissions
• Has great potential: Could generate 3% of UK's energy by 2020

Disadvantages:

• Technology would be expensive on a large scale
• Unreliable form of energy
• Devices could be far out to sea, so there may be high maintenance costs
• Equipment needs to be developed that can withstand poor weather conditions like storms

HOME - 25 billion homes in UK

Our homes are responsible for about 27% of carbon emissions and so energy conservation measures in the home could be an important way of reducing climate change

Ways in which energy can be conserved in homes:

• Smartmeter allows householder to see how much energy they're using
• Water tanks collect water from roof to flush toilets, feed washing machines (rainwater harvesting)
• Movement and daylight sensors mean lights only switch on when needed and turn of automatically
• Energy efficient boiler
• Mini wind turbines and solar pants
• 'A' rated kitchen appliances
• Energy efficient lightbulbs
• Double glazing to reduce energy needed for heating. Draught proofing, loft insulation and cavity wall insulation reduce heat loss

The govt is keen to ensure that the design and construction of any newly built homes are environmentally friendly, and so has introduced the 'Code for Sustainable Homes'

It was introduced in 2007 and aims to reduce our carbon emissions by 60% by 2050 and creathe homes that are more sustainable. The code will allow us to meet the target that all new homes from 2016 must be 0 carbon rated.

The code sets minimum standards for energy and water use at each level. The rating a home receives depends on how it measures up to 9 categories:

• energy and CO2 emissions
• water
• materials
• surface water run off
• waste
• pollution
• health and wellbeing
• management
• ecology

1 star homes = 10% more energy efficient and 20% more water efficient than most new homes

3 star homes = 25% more energy efficient and have more sustainable features than a 1 star home

6 star homes = highly sustainable and net carbon emissions would be 0. They are the most sustainable in the code.

New towns built in England are intended to achieve exemplary standards of sustainability. They should be carbon zero rated, should locally generate their own energy and be carbon neutral. Features of ecotown:

• Energy supply: Locally produced renewable energy e.g. from wind turbines and solar panels
• Waste management: Underground vacuum recyling systems and reclaimed and recycled water supplies
• Environment: Green and open spaces
• Transport: Bus stops 5 minutes from each house to encourage use of public transport
• Jobs: Jobs from local businesses to reduce travel
• Healthy living: Parks, green spaces and walkways

The Beddington Zero Energy Development was completed in 2002 and is Britain's first and only community experiment in 'zero-carbon'. BedZED is an award winning development of 99 apartments in South London. It aimed to be entirely sustainable and entirely zero carbon rated

Design features:

• Revolutionary wood burning technology to produce all the heat and power
• Thickly insulated and hermetically sealed apartments
• Solar panels and a wood chip powered heat and power plant
• Double or triple galzed windows
• Naturally ventilated using a roof funnel system
• Waste for recycling is collected
• Taps and showers fitted with flow restrictors
• Green water sewage system
• Large windows facing the sun for natural insulation

Successful:

• Solar panels produce 10% of power used by community
• Residents pay less than $400 a year for power and water
• Roof funnel system naturally ventilates apartments
• Each apartment emits about half a ton of carbon dioxide each year, half a ton less than homes built to standard bulding regulations

Unsuccessful:

• Not zero carbon rated or entirely sustainable
• Still releases carbon emissions
• Wood burning technology not producing enough energy
• Wood chip powered heat and power plant produce tar that clogs filters and is expensive to maintain

• Kirklees council has been cutting its own emission through installing solar panels and wind turbines. These cost saving measures have helped to find the 'warm zone' sustainable housing which launched in 2007.
• The project offers free insulation to every suitable house in Kirklees regardless of their financial means.
• Residents can apply for free energy efficient light bulbs
• A loan scheme offering interest free loans to install smale scale renewable energy technologies e.g. PV solar panels
• Warm zone is responsible for installing insulation in over 10,000 lofts and 5000 cavity walls

Transport consumes over 30% of the total energy supply of the UK and has shown the largest growth in demand over the past 20 years.

How to reduce environmental impact of transport:

• Walk or cycle
• Car share
• Drive efficiently to save fuel
• Use gas or electric cars
• Use more environmentally friendly fuels e.g. unleaded
• Public transport

Businesses in the UK is responsible for 40% of carbon emissions and has an important role to place in tackling climate change.

CASE STUDY: TESCO

• Emplying a low carbon emission strategy
• Stock delivered by train or barge instead of lorry
• Some lorries that are used use methane gas from rotten food to fuel the engine
• Drivers are monitored to make sure they are driving efficiently
• Cut road journeys by 9 million miles
• Halved greenhouse emissions from global transport system within 6 yrs
• 5 customer choice to choose low carbon products - signs and labels on over 100 products to inform customers
• Cut energy use by half by using natural lighting, rainwayer and more environmentally friendly gas to keep food frozen

Businesses in the UK is responsible for 40% of carbon emissions and has an important role to place in tackling climate change.

CASE STUDY: TESCO

• Emplying a low carbon emission strategy
• Stock delivered by train or barge instead of lorry
• Some lorries that are used use methane gas from rotten food to fuel the engine
• Drivers are monitored to make sure they are driving efficiently
• Cut road journeys by 9 million miles
• Halved greenhouse emissions from global transport system within 6 yrs
• 5 customer choice to choose low carbon products - signs and labels on over 100 products to inform customers
• Cut energy use by half by using natural lighting, rainwayer and more environmentally friendly gas to keep food frozen

• lower fuel duty on more environmentally friendly fuels
• road tax less for cars with lower CO2 emissions
• congestion charges in London
• electric and hybrid cars exempt from charges
• improvements to public transport
• park and ride schemes
• car sharing
• local councils monitor pollution levels
• catalytic converters in all cars
• unleaded petrol

The London congestion charge was introduced in 2003 and has charged drivers £8 a day to drive in the Central London Congestion Zone. The scheme was introduced because London has the UK's worst traffic congestion. In theory the congestion charge should encourage people to make more use of public transport, which is cheaper and more fuel efficient. The congestion charge has:

• Reduced traffic by 15%
• Cut congestion by 30%
• Bus passenger numbers have increased by 45% and cyclists by 45%
• Reduced nitrogen oxides and CO2 emissions by 12%

Car manufacturers are also developing 'green' cars. The most fuel efficient car ranked by the Department of Energy in 2009 is the Toyota Prius. This is an example of a hybrid car:

• Runs on electric and petrol
• Halves the emission of an average petrol car
• Lowers road tax
• Exempt from London's congestion charge

Despite this, it produces more carbon emissions during the manufacture of hybrid cars compared to the traditional cars.

London mayor, Borris Johnson launched a city wide cycle hire scheme. It is designed for short journeys with the first 30 minutes free. The scheme is set to expand to 200,000 bikes in the next few years. Since its launch, the hire scheme has been part of nearly 19 million journeys, and even in Feb 2013, the 7000 bikes in service are used about 10000 times a day. The scheme has helped to reduce the number of cars on the road along with carbon emissions.

Mexico city

Mexico City has a 'no driving today scheme' which means that vehicle owners are banned from city centre one day a week, the day depends on the number plate. It was set up in 1989 and still exists. IT has been coupled with an exhaust fume testing programme whereby each car is tested every 6 months. However, despite its success, wealthy residents have more than one car to get around the ban.