Energy: Fundamentals and Application

Week 2 Lecture by Alexander Hespe (Arup) 1/8/16

Pre – Lecture Task:

“A 40 Year Plan For Energy: Reinventing Fire” – Armory Lovins

(about 25 minutes long and very valuable)

This video describes the need for renewable energy and how to go about this, as well as the problems of continuing to use oil, coal or nuclear energy. Without any act of Congress, we can be oil and coal free, saving US$3Trillion. Technology, policy, design and business strategy are required as 4 parts.

2/5 of energy required to move a car it due to its weight. Cars weigh so much due to steel, which can be replaced with carbon fibre which is far lighter, requiring less force to move them, This results in smaller engines and can therefore be far more efficient to fuel through electricity. (230 miles per gallon – Voltswagon)

This principle can then be applied to large vehicle i.e. trucks and airplanes.

As efficiency is then increased (through various means), the need for other fuels (such as electric) will also decrease resulting in ever greater savings of both eergy and cost over time.

Smarter design – on windows, motors, pumps etc – can result in smaller technology requiremenents, such as a decreased cooling load in the case of “super” windows which are ffar more efficient than standard windows, which will therefore require less energy to manage and can have payback times of less than 5 years.

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Reflection:

This is a very clever speech on the problems with coal, nuclear and oil energy and the need to move to more sustainable answers: renewable energy. What is so clever about this speech, is Lovins’ ability to appeal to big business and government, in particular, by presenting the opportunities related to transitioning between fuel sources, rather than just labelling the costs associated with it. He describes this as an economic response, not just en environmental or a societal response, and that this transition will have business benefits and therefore is a “business opportunity”, rather than merely a moral response to the larger issue.

I think this is a very clever way to appeal to the larger groups in society who may have had doubts about the need to switch energy supply, or who may have not been able to see the positive affects this switch will have for them and their business.

Lecture

What is energy? The work done by a body or system.

Define the difference bwteen energy and power? Energy involves a time element (such as an hour), as opposed to the power used in a particular space of time.

Embodied energy – the energy within a produtc, that includes the full production cycle. For example, a brick’s embodied energy includes the the raw products, the firing of combining them, storing the products, transport of the product etc. That is, that static energy of a product even though the final product may not use energy or output energy. It is energy already “stuck” within the product.

1.1kg of CO2 is produced for each kWh of energy used (in Victoria, AUS. It’s about 0.2kg of CO2 in Tasmania, AUS). That means, that running your toaster for 1 hour (1 kWh) produces 1.1kg of CO2, which is quite significant.

For comparison, natural gas is around 0.27 kg of CO2 per kWh.

Carbon emissions are ranked as Scope 1, (personaly e.g. using your own diesel fuel) Scope 2 (provided to you e.g. power station)) and Scope 3 (external e.g. transport of Scope 2). These scopes are required as a means of context for any figures produced.

On site power energy generation

  • photovoltaics (solar panels)
  • wind power
  • solar thermal (for DHW, HHW etc)
  • fuel cells (ideal for baseload energy requirements)
  • Co- (or tri) genertion (combined heat plant CHP)

Energy storage

  • mechanical (e.g. pumped hydro, flywheel, compressed air)
  • electrical (e.g. electrochemical, capacitor)
  • thermal (e.g. ground source heat pump, ice storage, chiled water tank)
  • chemical (
  • organic/biological

Net Energy

Total energy, including energy gains and losses. Net energy definition and classification: Site, Source, Cost, Emissions.

How do we apply this information and technology?

Energy approach framework (from best option to last case options):

  • reduce (e.g. shading)
  • passive (e.g. natural ventilation, heat chimney)
  • efficiency (e.g. hydronic system)
  • re-use (e.g. heat recovery wheel)
  • renewable (e.g. wind turbines, BIPV)
  • offset

It is important ot consider WHEN in the design process these ideas are integrated. The earlier in the design ( i.e. scope and concept stages) will be the cheapest and generally more effective than at later stages.

Resources:

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