Harvesting Ocean Energy

Energy can be harvested from the oceans in five basic ways, with a multitude of variations.

1. Tides - Potential energy contained in tides can be harnessed by building barrage or other forms of construction across an estuary.
2. Waves - Kinetic and potential energy in ocean waves can be harnessed using modular technologies.
3. Tidal or marine currents - Kinetic energy in tidal (marine) currents can be harnessed using modular systems.
4. Temperature gradients - Thermal energy due to the temperature gradient between the sea surface and deepwater can be harnessed using different Ocean Thermal Energy Conversion (OTEC) processes.
5. Salinity gradients - At the mouth of rivers where fresh water mixes with salt water, energy associated with the salinity gradient can be harnessed using pressure-retarded reverse osmosis process and associated conversion technologies.

High-tech Technology in the Solar Thermal Industry

The solar thermal industry has used low-tech technology until relatively recently and been largely concerned with small domestic and building applications for heating space or water, or cooking by solar power. However, the solar thermal industry is now taking a more sophisticated direction and progressing to higher-tech solar power applications involving relatively large electricity generation projects in a number of countries. Some of these solar power electricity generation schemes have been in existence for a number of years on a trial basis.

Solar cooling, although still a very small application with around 80 solar cooling systems in the world, is making rapid strides.

Solar thermal collectors are divided into three categories, according to temperature, with low, medium, or high temperature collectors. Low temperature collectors are flat plates generally used to heat swimming pools directly. Medium-temperature collectors are also usually flat plates and are used directly for creating hot water for residential and commercial use. High temperature collectors concentrate sunlight using mirrors or lenses and are generally used for electric power production. These are known as CSP (concentrating solar power) units. In use described as ‘direct’ the solar energy or heat is used to heat water or buildings, or for factory process, and not transformed into electricity.

Wind Energy Industry Brought Surprises in 2008

2008 turned out to be a year of surprises in the wind energy industry. Global wind energy installed capacity was 94 GW by the end of 2007 and was estimated that it would reach 120 GW by the end of 2008. It has been doubling every three years during the last decade. The extraordinary growth in 2008 was due to unexpected increases (estimated) of 7 GW in China and 7.5 GW in the USA. It was not unexpected that these two countries did well but the scale of their growth was surprising. These two surges altered the global distribution of wind power, taking the US from 17.9% in 2007 to 20.2% in 2008 and China from 6.3% to 10.7%.

Global growth had slowed to 24% in 2006 but rose to 28% in 2007 and remained at that level in 2008.

The annual global wind market value in 2007 totalled €25 billion ($37 billion), an increase of 39% on €18 billion ($23 billion) in 2006 (in current values). Prices rose from $1.03 million per megawatt in 2005 to $1.21 million in 2006 and $1.26 million in 2007. The price rise was driven partly by the increase in demand but also by the increase in the price of raw materials, especially cold steel, which rose by 58% between 2005 and late 2008.

A Snapshot of Ocean Technology in 2009

Today, more than 25 countries are involved in developing relevant conversion technologies for harnessing ocean renewable resources for electricity generation and/or other purposes, such as desalination, heating for aquaculture and other uses.

Over 300 wave and tidal devices have been suggested up to the present time, but very few of these are in an advanced state of development. One technology, Pelamis, is leading in terms of development with a medium sized grid-connected scheme being installed in Portuguese waters now.

Ocean energy is mostly in an experimental stage and apart from the 40 year old tidal barrage at La Rance in France, the first ocean energy projects are now being installed and about to be commercialised.

The market is poised for expansion and is expected to grow to 1 GW of installed capacity at an annual market size of $500 million by 2015, but these figures are very broad. Investment to date in the ocean power market has been just over $500 million since 2001, which is relatively small compared to other renewable energy market segments. More than $2 billion will be invested to build commercial ocean wave power farms by 2015. Another $2 billion will go towards research and development globally over the next six years.

Solar Thermal Technology

Solar thermal is a relatively new technology which has already shown enormous promise. It is a larger energy source than is commonly perceived and currently provides about half the energy generated from wind power and more than geothermal, solar photovolatics and ocean energy combined. At the end of 2007 there was 93,000 MW of wind power, 148,000 MW of solar thermal collectors for water heating and building heating or cooling installed, but only 414 MW of high temperature solar thermal collector generating capacity and about 8,000 MW of solar PV capacity.

With few environmental impacts and a big resource, solar thermal energy offers an opportunity to the sunniest countries of the world, comparable to that currently benefiting European nations with the windiest shorelines.

Solar thermal power uses direct sunlight, so it must be sited in regions with high direct solar radiation. Among the most promising areas of the world are the South-Western United States, Central and South America, Africa, the Middle East, the Mediterranean countries of Europe, Iran, Pakistan and the desert regions of India, the former Soviet Union, China and Australia.

In contrast, solar photovoltaic cells use both direct and indirect, diffuse solar radiation and they are suitable in areas with indirect, diffuse solar conditions, such as many north European regions and is more effective in cold conditions.

In many regions of the world, one square kilometre of land is enough to generate as much as 100-200 GWh of electricity per year using solar thermal technology. This is equivalent to the annual production of a 50 MW conventional coal or gas-fired power plant.

Electricity Supply Industry in Sweden

Liberalisation and deregulation of the Swedish electricity market have been achieved ahead of target and by July 2000 all customers with access to the high voltage grid had free choice. The market has now been opened 100%.

The wholesale electricity market is considered competitive, as Swedish power generation is part of the regional Nordic market (which also includes Denmark, Finland and Norway). The electricity retail market exhibits higher than average switching rates.

Sweden is a member of Nordel, the Organisation for Electric Power Co-operation in Nordic Countries, a common electricity market which provides a market place for spot deliveries on a daily basis, as well as a market for financial contracts. As a resuIt, Sweden has 9 interconnections with Norway, 6 with Denmark, 5 with Finland and one newly completed with Germany. The connection with Germany is via the Baltic cable. This enterprise was established to place a 250 km DC cable with a capacity of 600 MW between Sweden and Germany.

Gas Meters Installed Base and Demand

There are 396 million gas meters in the world today with annual demand rising to an estimated 34.9 million in 2012. Accompanying this figure is a large number of refurbished meters, which have been verified, recalibrated, and used for replacement. Refurbishment of meters may increase if European countries follow in the footsteps of Germany, where new metrology regulations have removed the age limit and have increased the amount of refurbishment taking place in that country.

Unlike electricity and water, piped gas is not available in every country. Most of the piped gas is natural gas although there is still some city gas manufactured from coal or oil and some LPG is delivered by pipeline, mainly to industrial consumers.

Even within regions there are wide variations in the penetration of gas. For example, in northern Europe, Germany is the second largest gas consumer after the United Kingdom. However, the Scandinavian countries are small users of gas because of the use of coal in Denmark and hydropower in the other three countries, and increasingly nuclear, despite Norway being the largest gas producer in Europe and one of the largest in the world.

With global demand for LPG rising to 34.9 million meters in 2012, annual growth will be 4.0%. There will be variations in the growth rates in different regions of the world due to significant domination by a number of major markets. Growth of 8.7% in China, as the country converts from city gas to natural gas and the government promotes the use of gas as a clean fuel, extensive expansion of gasification in Russia, and continued growth in the USA at 5.5% will lift the world average, compensating for slower growth in other countries.

In value terms, the world market will grow to US$1.6 billion in 2012. The main growth will be in Asia, which will increase from US$439 million in 2007 to US$516 million, and Europe, which will grow from US$335 million to US$384 million. North America will increase from US$286 million to US$374 million.

The United States and Japan are the two largest markets for gas meters (with Japan including LPG meters). The US market is forecast to grow at an annual rate of 5.5% from 5.6 million meters in 2007 to 7.3 million in 2012. Gas meter growth will reflect surges in household growth and increasing AMR deployment. To date, the largest AMR installations in North America have been in the electricity utility sector; however, the gas utility sector is now expected to start gaining momentum.

Japan will grow by 1.4% from 5.2 million (piped natural gas and LPG) to 5.6 million meters in 2012. Growth will be considerably higher if installation of a new residential ultrasonic meter is not restricted to replacement of existing mechanical meters.

Growth in Europe will be the slowest, increasing at 2.8%. In the CIS, the intensive gasification of new regions of Russia will lead to growth of 4.4%, with slower growth in the other republics. According to industry reports, the market in Germany is in decline since metrology changes now permit gas meters to remain in service after 24 years, as long as they meet verification requirements.

China is the third largest gas meter market in the world with 29 million consumers and is poised to overtake Japan to become the second largest by 2010. The government’s decision to develop the natural gas market and to increase its share in primary energy holds significant challenges for local gas distribution companies, which are accustomed to distributing manufactured gas. The majority of Chinese cities have traditionally been supplied with manufactured gas, and there is now a need for a nationwide standardised approach to gas conversion. The largest single gas distribution company in Shanghai has 3.37 million customers.

The number of cities using natural gas has been predicted to increase to 270 in 2010 but this may be optimistic. India is still a small market for gas meters but will grow very fast in the next few years as new distribution networks for residential supply come into service. Demand for gas has grown by 6.5% annually and was expected to reach a rate of 13% in 2005. Two distribution companies (GCGL and MGL) have 450,000 customers between them, and Gail, the national natural gas transmission utility, has formed a number of distribution partnerships to expand distribution to 15 cities. The growth of customers and meters is estimated to be at least 15% per year.