Every time I see an adult on a bicycle, I no longer despair for the future of the human race.

- H G Wells
 

I have no doubt that we will be successful in harnessing the sun's energy...
If sunbeams were weapons of war, we would have had solar energy centuries ago.

- Sir George Porter
 

Windmills of Banning Pass, near Palm Springs, California, United States (N 33°57' W 116°42')
This landscape studded with wind turbines has become a classic sight in the United States and in northern Europe.
Germany is the world leader in the use of wind power. The use of wind energy, although still marginal in the world energy balance sheet
(its power exceeded 16,600 megawatts in 2001), underwent exceptional growth in the last three years of the 20th century.
Global wind power is expected to have exceeded 20,000 megawatts in 2002.
Renewable and nonpolluting, windmill energy uses the most modern methods developed by the aeronautics industry.
Source: www.yannarthusbertrand.com from Earth from Above by the incomparable photographer Yann Arthus-Bertrand

For years, New Zealand has enjoyed some of the lowest power prices in the developed world. Many people believe this was due to the large hydro-electricity schemes developed between the 1940s and 1970s.  The truth is, however, that the huge Maui gas field off the coast of Taranaki has set the benchmark for New Zealand's electricity prices for most of the last 30 years.  Today, Maui gas accounts for up to 25% of our electricity generation - but now it's running out.  By 2010 it is expected to be all but exhausted.  With New Zealand's economy growing and an increasing demand for power supply, we need to make some tough decisions now to avoid an energy supply "gap" that could disrupt our economy and our way of life.

New Zealand's energy solution is not a simple one.  The big issue is security of supply.  Solving the problem is a balancing act: security versus price versus the environment.  What are our energy options?  How do they affect our environment?  How will they affect the price of our power bills?  How much can we rely on them for our power supply?  These are just some of the questions we need to find answers to, to ensure power shortages are not the way of the future.  Please join the debate and try your hand at balancing our energy needs to help determine our energy future - it's all about positive energy.

How does it affect me?

What do I need to do?

Why are we telling you this?

The environmental impact of power generation comes in many forms.  For some technologies the impacts are predominantly local: discharges into rivers, emissions from power station stacks, or the noise and alteration or spoiling of the landscape associated with, say, an opencast coal mine or the development of a major hydro scheme.  Other impacts are more widespread.  Global warming is the ultimate example of an energy technology having local benefits and global costs.  The distribution of such impacts is also likely to be highly variable.  Some people may suffer significant direct impacts (for example. Bangladeshis suffering increased flooding, or farmers in parts of Africa who suffer increased drought), whilst others may appear to enjoy a "better" climate, even if native plants and animals start to change.

Many environmental impacts are intangible and difficult to predict.  For example, global warming may exacerbate water disputes between countries in politically volatile areas of the Middle East and Africa, and cause increased economic migration from peoples out of developing countries to more developed ones.  There are no easy answers.

New Zealand Is Lucky

We have a number of different options to help fill our energy gap over the next couple of decades.  Unfortunately, each of them comes with its own set of very different pros and cons.

Hydro

New Zealand has been blessed with many natural resources, not least of which are the major lakes and rivers which have been harnessed to provide hydro power.  Large scale developments last century mean that hydro now accounts for between 60 and 70% of total generation.

The Pros

	Clean and relatively abundant source of electricity
	Already supplies 60 - 70% of our needs
	Produces no greenhouse gases
	NZ has a wide range of potential sites, large and small
	Positive public perception of existing hydro plant and renewable energy generally
	Provides baseload generation - as long as it keeps raining

The Cons

	Strong and growing opposition to environmental impact of new big hydro schemes
	Reliant on weather - production can vary greatly from year to year
	Many new schemes would struggle to make electricity at competitive prices
	Most of best sites already used or off-limits
	Low hydro storage capacity in NZ
	Water becoming an increasingly scarce and expensive resource

Gas/LNG

New Zealand has two gas options: domestic natural gas from fields like Maui and Pohokura and imported Liquefied Natural Gas (LNG).  The electricity generation characteristics of both are identical, as are most of their pros and cons.

The Pros

	Significant untapped domestic resources known to exist
	Proven generation technology increasingly efficient
	Important existing source of electricity - producing up to 25% of total electricity, more during hydro shortages
	Relatively short power station construction times
	Relatively minor visual and physical impact
	Liquefied Natural Gas abundant on world market should local supplies run low
	Gas-powered plants can run 24/7 - perfect for security of supply
	Produces relatively lower cost electricity than most renewable energy alternatives
	Plants can be built close to source of demand - reducing costs of upgrading the national grid

The Cons

	Greenhouse gas emissions add to global warming - although much less so than coal
	Range of possible future costs for greenhouse gas emissions is very large
	Gas costs rising - Maui gas was very cheap by world standards - new domestic supplies already cost significantly more
	Local gas supplies uncertain - timing and size of local discoveries unknown, especially because of relative lack of new exploration in NZ
	Imported Liquefied Natural Gas would expose New Zealand electricity to fluctuations in world gas prices and foreign exchange rates

The only significant environmental impact from gas is the carbon dioxide (CO₂) that is emitted.  Modern combined-cycle gas fired power stations emit 2½ times less CO₂ than a modern coal-fired power station.

Coal

New Zealand has copious quantities of coal - equivalent to 30 Maui fields - which, if it were exploited, could serve New Zealand's needs for many decades.

The Pros

	Plentiful local supply
	Abundant overseas supplies
	Competitive with other new generation options if low or no carbon tax
	Reliable and available for baseload generation to ensure security of supply
	Relatively clean for local air quality, if using latest technology

The Cons

	Produces greenhouse gases
	Expensive source of electricity if high carbon tax
	Range of possible future costs for greenhouse gas emissions is very large
	Largest deposits of domestic coal located far from the centres of demand for electricity - costly to transport the coal or the electricity
	Coal-fired power stations are expensive to build - a lot of money to waste if a significant new gas field is found which makes New Zealand's coal capability redundant

Wind

Although there is plenty of wind in New Zealand, it also needs to be physically accessible, located close to the National Grid and not too environmentally invasive.  Additionally, wind power fluctuates with wind speeds, so it needs to work as a complement to more reliable energy sources, rather than as a stand-alone.

Middelgrunden offshore wind farm, near Copenhagen, Denmark (55°40' N, 12°38' E)
Since late 2000, the world’s largest offshore wind farm to date has stood in the Øresund strait, which separates Denmark from Sweden.
Its 20 turbines, each equipped with a rotor 250 feet (76 m) in diameter, standing 210 feet (64 m) above the water,
form an arc with a length of 2.1 miles (3.4 km).  With 40 mega-watts of power, the farm produces 3% of the electricity consumption of Copenhagen.
Source: yannarthusbertrand.com from Earth from Above by the incomparable photographer Yann Arthus-Bertrand

The Pros

	Non air-polluting
	Large, identified potential
	Renewable
	Well-suited to NZ conditions - abundant wind
	Complementary with hydro
	Technology improvements should lower costs, making some wind increasingly competitive as electricity prices rise

The Cons

	Expensive electricity at most identified sites, using current technology
	Major cost to transport power from remote site to National Grid - large scale wind development would require significant new investment in the National Grid
	Visual intrusion makes it inappropriate for areas of natural beauty
	Highly variable - depends on back-up being available from hydro and fossil fuel generation for times when conditions are too light or too severe to allow wind turbines to operate
	Community acceptance - potential noise and visual issues

In 2030 Denmark plans to satisfy 50% of its electricity needs by means of wind energy (as opposed to 10% today).
Although renewable energy makes up only 2% of primary energy used worldwide, the ecological advantages attract great interest.
Thanks to technical progress, which has reduced noise created by wind farms (installed about a 1/3 of a mile, or 500 m, from residential areas),
resistance is fading.  And with a 30% average annual growth rate in the past four years, the wind farm seems to be here to stay.
Photo source: trane.dk

Other Renewables

Renewable energy resources are those that are replenished naturally but limited in the amount that can be used at any one time.  Renewable energy resources include biomass, hydro, geothermal, solar, wind, ocean thermal, wave action and tidal action.

Geothermal

In many parts of New Zealand, volcanic activity heats up water underground to very high temperatures.  Geothermal power involves drilling deep wells to tap into this high temperature water to produce steam to turn electricity turbines.

The Pros

	Renewable energy using heat from the Earth's core
	Substantial untapped reserves
	Technology and efficiency improving
	Provides continuous generation - ideal for security of supply
	Some reserves would be relatively economic to develop

The Cons

	Wastewater and emissions require environmental control
	Potential for land subsidence
	Noise
	Potential impact on existing geothermal features of cultural or economic significance
	Some reserves would be costly to develop

Solar

The sun's energy can be directly harnessed in two main ways: solar heating of buildings or water, and electricity generation using solar cells (photovoltaics).

Photo source: rhlx01.rz.fht-esslingen.de visit their site for information on solar power as an energy source

The Pros

	Clean, abundant energy source
	Capable of being tapped simply through 'solar-savvy' architecture
	Improving technologies and scientific understanding of possibilities
	Growing public acceptance and uptake of solar water heating technology
	Solar space and water heating can be incorporated relatively cheaply when a building is being constructed
	Readily available to everyone doesn't require expensive national grid upgrades

The Cons

	Solar electricity generation using photovoltaics is expensive
	It is often expensive to fit solar heating into existing buildings
	Seasonal and regional variations - unreliable, daylight/weather-dependent

Biomass

Primary processing industries such as timber and pulp and paper plants generate waste biomass.  These by-products can be burned to produce steam and generate electricity with lower sulphur and nitrogen emissions than coal.

Already, 4% of our national energy supply is provided by woody biomass.

The Pros

	Uses materials that would otherwise be wasted
	Potential to lower energy costs on-site and reduce demand on national grid
	Cost-competitive in many cases
	Renewable resource

The Con

Waste materials need to be close to generation site to be economical

Tidal/Wave Action

Source: tidalelectric.com check their site for a novel approach to tidal power.
See rgu.ac.uk and www.fujitaresearch.com for other approaches.

Wave power involves converting the up and down motion of the waves into electricity using devices either fixed to the shore, or floating out at sea.

Tidal power involves capturing some of the energy that is inherent in moving vast quantities of water back and forth twice a day.  Tidal devices can either be large dam-like structures, or they could involve turbines anchored free within the tidal flow.

The Pros

	Clean, abundant energy source
	Potentially suited to New Zealand conditions
	Cost of technology likely to fall

The Cons

	Technology is currently expensive and in its infancy
	Relentlessly harsh environment
	Environmental and marine safety issues
	New Zealand tidal flows not especially strong

French Pass, which separates d'Urville Island from the South Island coast, is the only place in the world where two different levels of ocean can be seen at once.  This causes tremendously dangerous currents - sometimes the tide flows at up to 8 knots through the narrow Pass. Perhaps it would have strong enough flows to generate energy?

Energy Efficiency

The range of potential energy efficiency measures is as diverse as the range of different energy uses.

The Pros

	Very environmentally friendly - reduced energy consumption
	Very secure and reliable
	A significant cost-effective potential
	Social benefits - impact on housing warmth, dryness, respiratory illness, especially among the elderly and very young

The Cons

	Suffers from barriers to investment
	Consumers often are not aware of what they could do to save energy
	Or cannot be bothered
	Or don't have funds available to invest in energy efficiency
	Long payback times for some energy efficiency investments
	Retro-fitting existing buildings not always cost-effective

Nuclear

To many people, nuclear power is a fundamentally unacceptable option.  Concerns over nuclear are many and varied, including:

	nuclear waste will have to be stored for thousands of years
	the risk of accidents such as the one at Chernobyl
	possible deliberate terrorist strikes
	the problems of proliferating nuclear technology to politically unstable states'
	or even concerns that the cost of nuclear still isn't properly known given the uncertainties regarding decommissioning and waste disposal.

However, as concern about global warming grows, it is increasingly suggested that nuclear power should play a significant role in meeting the world's future electricity requirements.  Supporters of this now claim that the concerns highlighted above are no longer the problem they used to be and that nuclear now represents a clean, safe and cost-effective option. Most recently, noted environmentalist and author of the "Gaia" theory, James Lovelock, has added his voice to such calls.

Contact has not included nuclear as a possible option for New Zealand for two main reasons.  Partly this reflects the no-nukes stance that has been adopted by successive governments.  However, it also reflects the fact that it is not expected that a nuclear option would be commercially viable in New Zealand now or in the near future.  That is, among other reasons, because nuclear power relies on large economies of scale to achieve acceptable costs.  The smallest unit size commercially available is in the order of 600MW.  This is a very large unit size for the New Zealand, almost twice the current largest unit on the system.  A base-load unit of this size present a significant number of technical challenges.  It would simply not be feasible without significant changes to the way we operate the system to accommodate something of that scale in New Zealand for many years to come.

Source: positive-energy.co.nz - an important website.  Please give them a visit, including their facts and links pages - get involved!

See also: the preceding 3 pages (clicking "Back" below will get you to one) for more about peak oil, energy alternatives, the hydrogen economy and other stuff...

How the US Gets Energy (Interactive)

Source: msnbc.com

For pages on natural disasters - including lightning strikes, tornados, hurricanes, volcanoes, floods, and more - as well as some great satellite and tree photos, clicking the "Up" button immediately below takes you to the Table of Contents page for this Environment section.