To begin, these two videos neatly summaries how geothermal energy can be harnessed in the home for private use.
Figure 1: Explanation of geothermal energy with case study focus
Figure 2: Explanation of geothermal energy on a global scale.
Geothermal energy can be utilised to an effective extent as summarised in the figures 1 and 2. The possibilities that the earth energy possesses is now being used on a global scale as well as in the home and locally also.
Neal Hot Springs plant begins operation in and is generating 28 megawatts of electricity - enough to power over 25000 homes (The Associated Press, 2013). The plant system pumps water at around 300 degrees from a reservoir 2500 feet underground. This water vapor turns a turbine to run a generator - the water is returned to the ground at a temperature of around 140 degrees to be reheated again (The Associated Press, 2013). This process is completely renewable as the water vapor is recyclable back in to the system. It is estimated that the project cost $143.6 million (U.S. Geothermal Inc., 2013).
Neal Hot Springs Geothermal Plant. Source: reNews, 2012
Several hundred people worked on the construction of the geothermal plant and 20 ongoing jobs (The Associated Press, 2013a) are expected to continue to be offered in connection with the running of the plant. This shows how renewable energy power plant construction can have extra benefits on the wider community with the creation of jobs and more investment through salaries in to the local community. Many projects are associated also with training local people in running renewable energy programs.
This website provides a great source of information on the development of the project.
There are two types of solar panels: photo-voltaic (PV) and thermal. Figure 1 gives the best explanation I have found online of the main facts about solar power and its potential to be utilised in the home.
Figure 1: Introduction of Solar Power. Source: Solar century
PV panels use the suns energy to produce electricity, where as thermal panels use the heat energy from the sun to heat water. Both are feasible options, although it is thermal panels that are currently most popular in residential investment in England. Figure 2 shows a case study of a home owner who has installed renewable energy technologies and how he has benefited from this. The focus is on both solar PV and thermal panels along with a wind turbine that has been installed also.
Figure 2: Renewable Energy Technologies case study. Source: Energy Savings Trust, 2010.
There are Government initiatives to increase the interest in solar power potential at an individual level. The Green Deal is a Government initiative that is aimed at improving energy saving potential of homes and businesses. Figure 2 discusses the possibility of grants being available for help towards installation costs. As the Uswitch website shows, solar panels could be installed for free to lower the cost of energy bills if a scheme exists in the homeowners area. If qualification is not met then solar loans are available also, although this can be quite expensive in the long run. Figure 3 gives an explanation of the Feed-in Tarrif - another Government ran scheme that allows for homes to make a profit from their renewable technologies.
What is the Feed-in Tariff?
The Feed-in Tariff scheme is a government scheme that pays people for every unit of renewable energy they generate as an incentive to promote green energy. You install solar panels and start generating your own renewable electricity.
You use the free electricity you generate in your home, get paid for every unit you generate. If you need more, then you simply buy it from your energy supplier as usual.
You sell any extra electricity you're producing to the National Grid. You get paid per unit of electricity that you generate.
Tariffs are index-linked, which means they will track market prices and, depending on the type of technology you use to generate electricity, they're guaranteed for up to 20 years.
Information about solar panel installation is readily available on the web, with Tesco, Uswitch, Evo energy and the Energy Savings Trust all providing resources to help with progress towards greener energy production.
Tesco Home Efficiency makes solar panels more readily available and affordable to the public; however the prices are still quite expensive and it is not a cheap option in the short term despite the savings to be made in the future.
Evo energy provide much information to make solar panel possibilities seem much more accessible and feasible. The company works with the installation of Solar PV panels along with Solar Thermal panels.
The possibilities with solar power is a great investment as it is a technology that can pay for itself in the year after installation, however it is only available to those that are able to afford the initial cost. Uswitch state that the solar panels installed will pay for themselves within 9 years and will still be profitable for a guaranteed rate for a further 11 years. However, the rate at which electricity is produced or water heated is limited to the reliability that can be placed on the sun shining; less likely in winter months. Figure 4 shows that much can be earned from the PV installation as the money received is tax free.
Figure 4: Table to show how much can be earnt from the installation of solar panels. Source: Uswitch, 2013.
Benefits
The benefits from solar PV panels are plentiful.
The electricity produced is 'free' as it is powered by a public resource - the sun.
Uswitch (2013) claim that bills can be cut by up to 50%.
If solar panels are bought outright and the household qualifies for the 'Feed-in Tariff money can be earned on any excess electricity produced (Uswitch, 2013).
Produce electricity and heat water even when overcast - reliance is not upon the sun presence but more the intensity of the sunlight.
Hot water solar panels can be placed more freely.
Feed-in Tariff.
Lasts up to 25 years.
Excess electricity produced by PV panels can be exported to the grid.
Solar thermals save vast amounts of fueling costs on heating hot water, especially in summer months.
An understanding is gained of exactly how much energy is needed for living and where it can be saved
Disadvantages
Initial installation cost.
Ideally need to be South facing to be most efficient.
Are more efficient when the sun is bright (mainly the summer months)
The inverter will need replacing at some point within the 25 year life span - costing around £1000.
Maintenance.
Solar thermals need to be checked regularly for leaks.
Both PV and thermals need to be kept relatively clean to be most productive.
Uswitch (2013) Solar Panels, [online] available at: http://www.uswitch.com/solar-panels/ [accessed on 12th March 2013]Describe the two different types of panels & their success / costing / opinions.
Following on from my recent post on the Three Gorges Dam, I'd like to look at the productive possibilities that these hydroelectric wonders are capable of. Dams have long been used as a protective barrier against river flow and due to them being predictable and reliable the use of dams has developed in to an efficient way to produce and retain electricity.
The Hoover Dam is a great example of the prowess and incredible constructive capabilities of America around the time of the Great Depression. The aim of Davis the constructor was to build a high dam and deep canyon upstream to tame the out of control river. The dam spans Construction of the Dam was begun in March 1931 and shared between 6 major construction firms. It took two years to divert the river flow and bore out enough rock before work on the structure could start.
"no more floods, no more droughts"
This was Davis' aim. This has certainly been achieved and the Dam is classed as a modern civil engineering wonder and is recognised as one of the seven wonders of American construction.
Benefits of dams
Can be used to control the river flow; increasing irrigation of land whilst also preventing droughts and floods.
Electricity can be generated reliably, predictably and efficiently.
If constructed well a dam is safe and long lasting.
Drawbacks of dam construction
The construction of a dam is dangerous, although not so much nowadays as a century ago (96 people died building the hoover dam).
The cost is great.
The river flow is altered and the creation of a reservoir can lead to the displacement of thousands of people (as seen with the Three Gorges Dam where over a million people were displaced).
Loss of land also needs to be taken in to consideration with the reservoir construction.
Whilst researching I came across this recent Guardian article about the dangers of large dams in China on both national and global stability. The article focuses on China's five year plan from 2011 to 2015 that includes building 60 dams and 12 along their last free-flowing river. This is predict to harm ecosystems, displace people and cause catastrophic seismic events; due to the increased pressure of the water on an already earthquake prone area. The link to the article is below:
This is an interesting article I came across today; highlighting future problems with the increasing development of renewable energy in America. The adaptations for the growth in this sector is not yet in a position to be able to cope with increased production and subsequent distribution.
The article focuses on how Germany produces renewable electricity with much success:
"It’s not magic — it’s actually pretty logical and straightforward. And the benefit Germany gets is tremendous: a high proportion of 100 percent clean electricity with solid reliability."
Much can be learnt from how Germany has developed within this sector. Both these articles provide insight in to the issues that can arise from increased use of renewable energy technologies.
