Add consumption

[peterdudfield]

Detailed Description

It would be nice to add generation into this package. This means you can add a consumption of a building, and then see how the battery should operate.

Possible Implementation

• add consumption here https://github.com/openclimatefix/solar-and-storage/blob/main/solar_and_storage/solar_and_storage.py#L17
• add to objective function
• Problem: work out how to set up Linear Optimzation with Solar+storage + consumption
• add example, with plots

[peterdudfield]

We might be able to sove this by combing consumption and solar generation to be
generation = solar generation - consumption. Then we just use generation like we have before. This might work?

[gilbertgong]

I'm testing a version in which net_generation = solar_generation - consumption which should definitely work in principle. It does become a bit more complicated, the current constraints are set up with the expectation that solar_generation is >= 0, which of course is true with actual generation, but if we allow net_generation to be negative (due to consuming more than we're generating), then a bunch of the constraints need to be adjusted. working through that now but it's going to take some thinking..

[gilbertgong]

Ok I'm reconsidering if net_generation = solar_generation - consumption is the way to go. Because we have to take into account a lot of different cases, like using power from the grid for consumption, using battery for consumption, charging the battery while using the grid for consumption, etc. So regardless there's going to be a bunch of constraint changes, in which case probably incorporating consumption directly will be easier to understand.

[gilbertgong]

I'm pretty deep into this now, but I'm starting to have some questions..

Take this:

        profit = self.prices * (
            self.power_discharge_cp_variable.value - self.battery_power_charge_cp_variable.value
        )

Is "profit" supposed to mean only the money generated from selling from the battery? Shouldn't profit include revenue from solar being sold directly to the grid as well? Or do we want a separate "battery profit" and "solar profit"?

[peterdudfield]

Thats great you are getting in to this.

if its possible to split it then, then do both yea. Is it possible to split them up easily? As in if some of the energy goes straight into the battery from the solar, where does that count?

[gilbertgong]

Well, right now the profit var is actually just the battery profit, as it's counted as self.power_discharge_cp_variable.value - self.battery_power_charge_cp_variable.value (power_discharge_cp_variable represents

         # the amount of power going out of the battery
        self.power_discharge_cp_variable = cp.Variable(HOURS_PER_DAY)

solar profit would be self.prices * solar_to_grid, solar that goes to the battery would be part of battery profit. solar profit is simply ignored in the code right now, so actually the current profit numbers are basically incorrect if it was supposed to represent both solar and battery profit.

But yeah, i can fix this..

[gilbertgong]

Also I want to check my understanding. I just noticed this:

            power_charge = (
                self.eta_charge * self.battery_power_charge_cp_variable[i]
            ) + self.power_solar_to_battery[i]

is the efficiency factor applied only to the grid charging because we assume DC to DC charging on solar to battery, which is assumed to be more efficient?

If yes I'll add some comments to clarify the reasoning..

[peterdudfield]

yea, I think so, yea clarifying comments would be great