Utilisation Factor

[Mia McLachlan]

Hi all, 

When analysing our results, we have observed a trend which is the opposite to what we are expecting. We are worried that this is because our definition of the utilisation factor is incorrect. The way we defined it meant that more thermally efficient technologies such as electricity had a lower utilisation factor because less time was required to cook the same item than with a less thermally efficient stove. 

Could you please define utilisation factor in terms of demand and installed capacity so we can check that we are understanding it correctly? Could you also please confirm whether thermal efficiency is proportional or inversely proportional to utilisation factor?

Thank-you,

Avi & Mia

[Alexander Kell]

Hi both,

I think your understanding of utilisation factor in this case is wrong. A lower utilisation factor means that you need a higher capacity to meet the same demand. Effectively, the utilisation factor is the amount of time that a technology is used in a period divided by maximum possible time that it could be used. It is often lower due to enforced and unwelcome downtime. Basically, the higher the utilisation factor the better.

Thermal efficiency is different to the utilisation factor. The thermal efficiency tells us how much input energy is converted into useful output energy. The lower the thermal efficiency, the "worse" the technology. 

Best wishes,

Alex

[Mia McLachlan]

Aha I see,

In the context of stoves, should the utilisation factor be the same for each technology then, if not a function of thermal efficiency?

Best,
Avi & Mia

[Alexander Kell]

I imagine they would be similar. The differences would be in terms of reliability. Can users rely on a wood stove 100% of the time? Or are there times when they can't source the fuel? If so, that would bring down the utilisation factor (UF). Perhaps an electric stove would be more reliable when there is power, but maybe the power supply drops more often?

I think if you can't find concrete data for these, then you should make some assumptions and ensure they're explained in the report.

Thanks,

Alex

[Mia McLachlan]

Ahh we understand, just to confirm, the required installed capacity will be calculated by the model by dividing demand by the utilisation factor and the thermal efficiency.

Best Wishes,

Avi & Mia

[Alexander Kell]

The required installed capacity is equal to demand divided by the UF. If you factor in the thermal efficiency then you will be calculating the amount of fuel required to meet the demand using that technology. The thermal efficiency is defined in the CommIn.csv file.

Thanks,

Alex