Kilowatt.ie runs a simulation of your electricity imports and exports for each half-hour time slot over the course of a full year.
Based on this, we can rank every kind of electricity tariff on cost.
General Assumptions
- For comparisons based on your kWh consumption or the “National Average” (4,200 kWh per annum), we assume the following split across times of the day (flat within each time band):
| Band | Hours | Units | Proportion | Average Power |
|---|---|---|---|---|
| Peak | 5pm – 7pm | 420 | 10% | 0.57534 kW |
| Night | 11pm – 8am | 2226 | 53% | 0.47306 kW |
| Day | All other times | 1554 | 37% | 0.46913 kW |
- We assume you’re willing to pay by direct debit and online billing if required to obtain the best price
- “Cashback”, “Welcome Bonuses”, and unit rate discounts are included in the calculations.
- It’s standard practice for electricity suppliers to jack up prices once your contract expires. To get a good value, you need to re-evaluate your options and most likely switch again as soon as your contract expires. Mark your calendar!
- All prices include VAT
Battery Simulations
Batteries are assumed to be AC-coupled, and have a round-trip efficiency of 87%, unless otherwise specified. Capacity refers to the usable discharge amount on the AC side per cycle.
We assume max charge/discharge rates according to the following table, unless otherwise specified.
| Battery Capacity | Assumed Max Charge/Discharge Rate |
|---|---|
| 1 kWh | 1 kW |
| 2 kWh | 2 kW |
| 3 – 6 kWh | 3 kW |
| 7 – 10 kWh | 4 kW |
| 10-24 kWh | 6 kW* |
| >24 kWh | 11 kW** |
** Approx three-phase limit
EV Charging Simulations
EV charging is assumed to start at 2am each night, and continue until the specified number of (AC) kWh have been consumed.
We assume that you charger runs at 7kW (AC)
For EV charging, all energy/power amounts refer to the consumption by the charger. This will be slightly higher than the energy delivered to the EV battery due to conversion losses inside the charger
Solar Panel Simulations
We simulate the performance of solar panels using Typical Meteorological Year data for the centre of your chosen county.
Inverter AC power is assumed to be limited to 5kW. Clipping is assumed above this amount.
Within each given half-hour time band, we assume that any simulated solar production can be used to offset imports.
Heat Pump Simulations
Heat pump simulations assume that heating is when the outside air temperature is below 16°C, linearly increasing as the temperature decreases below that point.
We source temperature data (both for heat demand and air-source heat pump efficiency) from the typical meteorological year for the centre of your selected county.
For gound-source heat pumps, we assume a COP of 4.25, regardless of air temperature.
For air-source heat pumps, we assume a COP of 3.25 for an air temperature of 0°C, increasing by 0.0875 for each degree of temperature increase above 0°C and decreasing by the same amount for each degree of temperature below 0˚C.
We also assume an always-on approach to heating control for the heat pump.