“Baseload” – why words matter

The electricity sector often throws out the word “Baseload” or “Baseload Demand”.  The word has been used so often that it has taken on a new meaning, with users confusing the concept of baseload demand, and baseload generation.

In fact, word baseload has become so closely connected with generation, that it no longer has any meaning related to load. 

We need new words to describe demand.  I would argue that we need to rename “baseload demand”, which the electricity sector routinely confuses with generation, with “minimum load”.

Electricity systems have a minimum load.  This is the minimum amount of electricty that is required.  In Ontario, our minimum load is about 13,000 MW’s.  Our peak load is about 27,000 MW’s, and our average load is about 17,500 MW’s. 

Of course the minimum load is not the minimum.  In times of widespread blackouts, where customers can’t get power, load will be less.  And aggressive conservation, or a recession can reduce the minimum load.  But for planning purposes, we will accept that there is a minimum.

The question is, how do we best supply the minimum load?  And this is where many become confused, and begin talk of “baseload plants”. 

Why should we dedicate a plant to providing baseload?  We are making an enormous invesment in capacity to meet peak demands.  If we also invest in baseload generation, then we will use our peaking plants less.  This will amortize their capital cost over less hours of use, and make them enourmously expensive sources of power.

In Ontario, I would suggest we have ample, or perhaps too much baseload generation.  And we are contracting for more.

We have about 1000 MW’s of natural gas co-generation.  This runs in conjunction with industrial processes that require heat 24/7, and generate electricity on the side.  This form of generation is very efficient, turning up to 80% of natural gas into heat or electricity, compared to 40-60% for a normal natural gas plant.  It can’t easily be turned off.  So it supplies minimum load.

We have about 3000 MW’s of waterpower that runs all the time.  It supplies minimum load. 

And we have 11,500 MW’s of operating nuclear, which is very difficult to shut down, and requires days to re-start.  It is a dreadful way to supply peak load.  Shutting down plants on low demand is every bit as critical to system reliability to turing on plants to meet peak load. 

So we already have 15,500 MW of baseload generation to meet our minimum load of 13000 MW. 

That is probably why the spot price for electricity was negative last night.

So there is no clear need for more baseload supply, to meet our minimum load. 

Yet despite this, the Ontario Power Authority contracted with the Bruce plant to refurbish an additional 1700 MW’s of supply, that is due to become available around the end of the decade.   

The OPA forecasts that demand in the province will rise by about 1%/year.  So by 2010, the minimum load will be about 13,500 MW’s.

Assuming that the rest of the nuclear plants continue to operate, and that our waterpower and co-generation does not change (but there are new contracts for them too), we will have 17,200 in baseload generation to accomodate minimum load of 13,500.

And the Ontario government is proposing that we build a new nuclear plant, in a decade or so.

The only way this profigate investment in new and refurbished baseload generation plants can be justified is if we are planning on shutting down, and not refurbishing, existing nuclear plants.  Or perhaps the spending can’t be justified.

Either way, we deserve an answer.



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