THE SUN

The sun is probably the most important source of renewable energy available today.

Sunlight, or solar energy, can be used directly for heating and lighting homes and other buildings, for generating electricity, and for hot water heating, solar cooling, and a variety of commercial and industrial uses.

The sun's heat also drives the winds, whose energy, is captured with wind turbines. Then, the winds and the sun's heat cause water to evaporate. When this water vapor turns into rain or snow and flows downhill into rivers or streams, its energy can be captured using hydroelectric power.

Along with the rain and snow, sunlight causes plants to grow. The organic matter that makes up those plants is known as biomass. Biomass can be used to produce electricity, transportation fuels, or chemicals. The use of biomass for any of these purposes is called bioenergy.

WHAT IS RENEWABLE ENERGY?

A sustainable energy source can be defined as one that:

• is not substantially depleted by continued use
• does not produce significant pollution or other environmental problems
• does not cause health hazards or social injustices.

In practice, few energy sources come close to these ideals, but renewable energy sources are generally more sustainable than fossil or nuclear fuels: they are essentially inexhaustible, and their use usually involves fewer health hazards and much lower emissions of greenhouse gases and other pollutants.

There are many forms of renewable energies:

Solar. This form of energy relies on the nuclear fusion power from the core of the Sun. This energy can be collected and converted in a few different ways. The range is from solar water heating with solar collectors to the complex technologies of direct conversion of sunlight to electrical energy using photovoltaic cells.

Wind Power. Wind energy can be used to pump water or generate electricity, but requires extensive areal coverage to produce significant amounts of energy. 

 Hydroelectric energy.  Water power is power derived from the energy of falling water or fast running water, which may be harnessed for useful purposes. It is not strictly speaking renewable since all reservoirs eventually fill up and require very expensive excavation to become useful again.

 

Biomass is organic matter derived from living, or recently living organisms. Biomass can be used as a source of energy and it most often refers to plants or plant-based materials which are not used for food or feed, and are specifically called lignocellulosic biomass . As an energy source, biomass can either be used directly via combustion to produce heat, or indirectly after converting it to various forms of biofuel. Conversion of biomass to biofuel can be achieved by different methods which are broadly classified into: thermal, chemical, and biochemical methods.

Geothermal power is Earth energy, a result of the heat storage in the Earth's surface. Soil everywhere tends to stay at a relatively constant temperature, the yearly average, and can be used with heat pumps to heat a building in winter and cool a building in summer. This form of energy can lessen the need for other power to maintain comfortable temperatures in buildings, but cannot be used to produce electricity. 

Other forms of energy. Energy from tides, the oceans and hot hydrogen fusion are other forms that can be used to generate electricity.

LOOKING AHEAD & REFLECTION WEEK 8

Looking back at the first week of this course I hadn't realized how many processes affect our climate, how we contribute to climate change and most importantly how we can prevent further damage to our planet and surrounding atmosphere. 

Particularly important to me is that this course gives me the opportunity to learn and widen my knowledge. Snowball earth, feedbacks, ocean acidification, the Artic, Antarctica, green house gases, climate models, all of this topics were really interesting for me.

 

 

In this last week, professor Tim Lenton said: Our collective actions will determine the future climate for many, many generations to come.

 

He makes me think about which actions we can take against climate change.

The Kyoto Protocol 1997 committed industrialised nations to reduce their carbon emissions. But the protocol expires in 2020, and the United Nations are working on a new agreement to keep climate change within safe levels of less than 2 degrees of global warming above the pre-industrial level. Any international agreement to meet the two degrees target requires a roughly 60% reduction in global carbon emissions.

It's easy to set targets, but it's not so easy to take the steps that are necessary to meet them.

In Spain, The spanish government has launched a range of urgent measures in the most relevant sectors regarding the need to reduce carbon dioxide emissions, identified such as “The Strategic Lines against Climate Change”, six lines with the aim of being accomplished in two years time since July, 2008. The Strategic Lines affect a wide range of sectors such as transports, waste and manure management, residential, energy, forestry and innovation. The Spanish Energy Policy is based on three axes; Security supply, competitiveness and sustainability. 

 

http://climate-adapt.eea.europa.eu/countries/spain

http://www.magrama.gob.es/es/cambio-climatico/temas/impactos-vulnerabilidad-y-adaptacion/folleto_pnacc_ing_tcm7-197095.pdf

But, what action can individuals take?

Here, I write some individual actions that we can do but I am sure that there are more.

 At home - reduce, reuse, recycle

• Buy minimally packaged goods.
• Recycle paper, plastic, glass, and metal. Reuse, mend, and repurpose things to save money and divert waste from your local landfill.
• Plug air leaks in windows and doors to increase energy efficiency.
• Adjust your thermostat, lower in winter, higher in summer.
• Replace old appliances with energy efficient models and light bulbs.
• Save electricity by plugging appliances into a power strip and turning them off completely when not in use.
• Wash clothes in cold or warm water.
• Run dishwashers only when full and don’t use heat to dry dishes.
• Eat less meat, poultry, and fish.
• Plant Trees – Enter tree planting pledges online, then plant indigenous or locally appropriate trees where you live. 

At work

• Print double-sided or not at all.
• Always use reusable cups, knives and forks.
• Think before you travel. If a video conference call will suffice, spare the hassle and expense, and CO2 emissions.
• Avoid traffic jams and decrease your personal carbon footprint by walking, bicycling, and using mass transit whenever possible. Consider carpooling with friends, neighbors, and co-workers.
• Taking the stairs can sometimes be faster than waiting in long elevator lines. In addition to saving energy, taking the stairs gives you a mild workout which will help keep you healthy.

 

The Energy Saving Trust has a useful website that defines what is meant by a carbon foot print as well as looking at what measures might be taken to reduce them.
http://www.energysavingtrust.org.uk/domestic/

You can calculate your carbon footprint using the WWF calculator


I would like to finish this course with this quote.

REFLECTION WEEK 6 AND 7

In these two weeks I have learnt new concepts that I didn't know.

The first one was the concept of heat island a metropolitan area that's a lot warmer than the rural areas surrounding. Thinking about this topic I realize that Ourense in summer is a heat island. Often in summer period people use to go to villages to avoid the high temperatures and the electricity consumption for air-conditioning increased spectacularly. Last year the thermometers show temperatures near to 45 degrees in some areas of the city.







In week 6 we also saw the problem of food security. Climate change will influence healthy food availability, the effect of fungy can cause diseases on our crops of wheat, rice and maize and of course the diseases threaten our food suply. Another cause of the lack of crops in the future is the use of monoculture because this form of agruculture puts the security of our food supply at severe risk.

 So, how can we tackle the lack of food supply in the future?
There are some options that people have considered during the discussion.
1. Reduce food waste. 
2. Diversify our crops.
3. Reduce meat consumption.
4. Family planning schemes.
5. Improve soil fertility.
6. Become vegetarian.
 What is/are the good idea/s? I don't know but there are probably many more actions to bear in mind.

In week 7 we go into the basic concepts of building design and the nimbys action.
We need a building energy efficient, comfortable, affordable and ecological at the same time. Here is the passive house which allow for heating and cooling related energy savings of up to 90% compared with typical building stock and over 75% compared with average new builds.

It is still claimed by some that Passive Houses are not affordable but the construction of Passive Houses is profitable if they are built and designed competently.  

Finally, the NIMBY concept that is liked really close to the use of renewable energy. It is a pejorative characterization of opposition by residents to a proposal for a new development because it is close to them, often with the connotation that such residents believe that the developments are needed in society but should be further away.