If your business has never signed a contract with a retail electric supplier, you are on ComEd's default supply service. In the tariff it is Basic Electric Service, and it comes in two forms: a conventional version and an hourly-priced one, Rate BESH, where the price of energy changes every hour of every day.
Salespeople rarely raise BESH, for the obvious reason that they cannot sell it to you. That does not make it right for you. It makes it unmentioned, which is a different problem.
What BESH actually changes, and what it leaves alone
It changes one half of one half of your bill.
Your bill splits into supply and delivery. BESH is a supply option. It changes what you pay per kilowatt hour and when. It does not touch the delivery side, which means it does not touch your demand charge, the line that on many commercial accounts is larger than the entire supply cost.
This is worth being blunt about, because the disappointment pattern is well documented. A business changes something on the supply half, the bill barely moves, and the conclusion drawn is that there was nothing to find. There was. It was in the other half, and no supply decision of any kind reaches it.
So the honest framing of BESH is narrow: it is a way to pay a different price for the energy you use, and its upside is bounded by how large your energy cost is relative to everything else on the bill.
The question that decides it, and it is not the average price
The tempting comparison is the wrong one: take the average hourly price over the last year, compare it to the fixed rate you were quoted, take the lower number. That comparison would be right only if your business used the same amount of power in every hour of the year, and no business does.
What matters is when your load runs. Hourly prices are not evenly distributed. They are low for most of the year and violent for a small number of hours, mostly summer weekday afternoons. A business whose load is concentrated in exactly those hours is buying at the worst moments of the year, and its average is nothing like the market's average. A business that runs overnight, or through the winter, or on weekends, is buying almost entirely in the cheap hours.
Two businesses on the same rate, with the same annual kilowatt hours, land in different places. The average price cannot tell them apart. Their load shapes can.
What you already have that answers it
You do not need a projection and you do not need to sign anything to find out.
Your bill tells you the size of the prize. Find the supply portion of your annual cost. If supply is a small share of your total, then even a good outcome on BESH is a small outcome, and the effort belongs on the delivery side instead. That is a legitimate and common answer.
Your operating schedule tells you the direction. You already know whether your heavy loads run at two in the afternoon in July or at four in the morning in January. That is the single most informative input, and you have it without any data export.
Your interval data tells you the number. ComEd records your usage every half hour and will hand the record back to you. Applied hour by hour against the hourly prices for the same period, it produces what you would actually have paid, not what an average implies. That is the only version of this comparison that is worth acting on, and it is a backward-looking measurement rather than a forecast.
The exposure to be honest about
Hourly pricing moves risk onto you. In the ordinary year that is a good trade for a business with flexible or off-peak load. In a bad week it is not, and the bad weeks are correlated across the whole region, which means they arrive when everyone else's costs are rising too.
A fixed rate is not a cheaper product. It is the same product with the volatility sold back to you at a price. Whether that price is worth paying is a question about your tolerance and your margins, not about the electricity market, and nobody can answer it from outside your business.
What is ComEd Rate BES?
Basic Electric Service, the default supply a ComEd account receives when it has not contracted with a retail electric supplier. ComEd procures the energy and passes the cost through; it is not selling you energy at a margin.
What is the difference between Rate BES and Rate BESH?
BESH is the hourly-priced form. The energy price changes every hour rather than holding a single rate across the billing period.
Does hourly supply reduce my demand charge?
No. The demand charge sits on the delivery side of the bill and is set by your highest qualifying half hour of draw. Supply pricing of any kind, hourly or fixed, leaves it untouched.
How do I know whether hourly pricing would have saved my business money?
Apply the hourly prices for a past period against your own half-hourly usage for that same period. That produces a measured result for a year that already happened, rather than a projection of one that has not.