One more debatable C&G exam question!

[rich1]

One more and I think this is a really dumb question:

Which of the following micro-generation systems required LEAST maintenance once installed?
a) Biomass
b) Solar thermal
c) ASHP
d) Micro CHP

Clearly a) and d) are going to be higher maintenance.

ASHP and Solar thermal? Hmmm. I'd say even.

Looking at the course notes for ASHP, it specifically says its a 'fit and forget' system. It says nothing about maintenance on solar thermal. So I think they want me to answer ASHP. Wrong!

The 'correct' answer is b).

I've been told by people who work on these systems that there is no difference in maintenance between these two.

Obviously solar PV would be the lowest maintenance but thats not one of the opotions...

 

[binky]

solar thermal needs checking around every 5 years, it runs antifreeze through the panels, which needs checking, just like your car.

 

[ProDave]

And as an ASHP user, they don't require any routine maintenance.

 

[runningpiglet]

Surely ASHP is not a micro-generation system - it is an energy consumer?

 

[offgridAndy]

Surely ASHP is not a micro-generation system - it is an energy consumer?

correct. go to top of class

 

[rich1]

Surely ASHP is not a micro-generation system - it is an energy consumer?

Ahhh! Good point!

But doesn't an ASHP pull energy out of the environment just like wind, solar and other renewables. After all it generates 3x more heat than the electrical energy in consumes, so it's a net generator.

All of the mentioned systems are in the section of the course notes called Micro Renewable Energies.

 

[offgridAndy]

There is no such thing as a free lunch, or magic energy creation. The heat is extracted from the atmosphere (thanks sun) and the electric is consumed in the conversion process.

 

[poni]

After all it generates 3x more heat than the electrical energy in consumes

does that not make it just more efficient than other heating appliances, rather than a generator?

 

[ProDave]

does that not make it just more efficient than other heating appliances, rather than a generator?

An ASHP is typically 300% to 400% efficient. So you could get 4 times the heat out than the electricity consumed to make it do that.

It's not magic, that extra energy has come from the air outside, you have cooled down a lot of air and in so doing extracted energy from it. So some people regard this as micro generation, or at least renewable heat.

 

[rich1]

There is no such thing as a free lunch, or magic energy creation. The heat is extracted from the atmosphere (thanks sun) and the electric is consumed in the conversion process.

Yes but the question is, is an ASHP considered micro-generation? I say it is due to it extracting energy from the air and doing it at at least 3X efficiency. Solar thermal also requires additional power to operate so it falls into the same camp. Solar PV works without any other power input as does a wind turbine.

If we accept all the options are micro-generation, the real point is that there is no clear correct single answer to the question and the C&G course notes point the student to the 'wrong' answer.

 

[rich1]

does that not make it just more efficient than other heating appliances, rather than a generator?

No, it's no different than solar thermal. It moves heat energy from one place to another and both require an additional electric power source to operate. If I really wanted to knit pick I'd say a 'generator' converts one type of energy to another... maybe? But the question is, in the list of possible answers, is an ASHP micro-generation?

 

[SPECIAL LOCATION]

If we accept all the options are micro-generation, the real point is that there is no clear correct single answer to the question and the C&G course notes point the student to the 'wrong' answer.

Is this a 'self-study-at-home-online-type-course' you are doing rich1?
and/or do you have access/contact details to a tutor who you could ask for a bit more guidance as to what C&G reasoning is for this question?

Its been a while but I am sure that back in the days of my old classroom based teaching, I recall when questions were asked the tutor(s) often had notes referencing to a section of the Wiring Regulations, Guidance Notes, On-Site-Guide, Other BS/HSE/Statutory document(s) etc.. that would assist with explaining the objective and expected answer for a question?

 

[rich1]

Is this a 'self-study-at-home-online-type-course' you are doing rich1?
and/or do you have access/contact details to a tutor who you could ask for a bit more guidance as to what C&G reasoning is for this question?

Its been a while but I am sure that back in the days of my old classroom based teaching, I recall when questions were asked the tutor(s) often had notes referencing to a section of the Wiring Regulations, Guidance Notes, On-Site-Guide, Other BS/HSE/Statutory document(s) etc.. that would assist with explaining the objective and expected answer for a question?

No its at college. I queried it with the tutor and didn't get any reasonable reply, other than that his opinion of the questions was just as poor as mine!

In this case it was a mock exam, the real one is due after Easter and we don't get to see the right and wrong answers in the real exams.

 

[SPECIAL LOCATION]

No, it's no different than solar thermal. It moves heat energy from one place to another and both require an additional electric power source to operate.

I may be wrong... But technically, (although its not done as the solar thermal panels are typically already at the highest point of a property), I think it would be actually possible to create a solar thermal with NO electrical source needed at all...??

e.g. Older early gas central heating systems often just used a gravity system, (no pump) to create a flow of water, on the "Hot water rises", and "Cold water doesn't" principle!.
So Boiler heats water.. Hot water rises creating a flow around the pipe circuit.

So if a solar thermal panel was fitted lower down, the warmer water heated by the sun would start to create a flow up and around the pipes..?

Which as you say would be simply capturing heat energy and moving it without actually generating anything by consuming an alternative source of energy..

I think I would agree with your basic assumption that a generator consumes one source of energy to create a different type of energy.. Some dictionary definitions refer to devices creating electricity, others describe devices that convert mechanical energy?

But for example, as far as I know... you cannot generate Gas, or Petrol, or Diesel, or Wind, or Sunlight.. But they can all be extracted, processed and/or captured to generate electricity..

Electricity is not floating around in the atmosphere, or buried in the ground awaiting extraction.. So it has to be "generated" in one form or another? Hence some definitions describing Generators as devices that create Electricity.

 

[Fleeting]

Mock exam questions very often do not crop up in the real exam. Your tutor sounds typical of the modern system, they follow the guidelines and can offer no argument because they are clueless and technically inept.

 

[rich1]

Mock exam questions very often do not crop up in the real exam. Your tutor sounds typical of the modern system, they follow the guidelines and can offer no argument because they are clueless and technically inept.

Yes, I hope the real exam has questions that are taken from the actual course material and on-site guide rather than just made up on the fly!

The tutor is actually pretty old school and as I'm a lot older than the rest of the students, perhaps he wasn't prepared for a discussion on the finer details of the questions and answers! He's only recently started teaching us so I can't say what make of him yet.

Anyway, it did bug me that questions came up that require answers that cannot be found in the material provided. I'd be ok with the answer being technically wrong as long as the course material was also technically wrong. The answer simply proving that you'd learnt the information provided.

 

[SPECIAL LOCATION]

I'd be ok with the answer being technically wrong as long as the course material was also technically wrong. The answer simply proving that you'd learnt the information provided.

I am 100% sure that I recall several mock exam questions being wrong!!!

Basically someone tries to slightly tweak a real exam question..

But then cocks-up the classic C&G double negative element, to create a completely wrong question and selection of answers!!!