As a rule of thumb, when using fossil fuels to make electricity, grid electricity is 1/3 efficient, and cost three times as much as having an appliance that uses the fossil fuel directly.
Of course there's plenty of details that make that statement an over simplification! The point is that you can recuperate your investment in a fossil fuels based heater extremely quickly.
Another problem with using electric water heaters is that they pull a high amount of amperage. Assuming you're going tankless, a water heater necessary for the temperatures in the northeast states could easily use over 100 amps. If you fill the bathtub, turn on the oven, and charge the car at the same time, you could trip your main breaker.
Of course there's plenty of details that make that statement an over simplification! The point is that you can recuperate your investment in a fossil fuels based heater extremely quickly.
Another problem with using electric water heaters is that they pull a high amount of amperage. Assuming you're going tankless, a water heater necessary for the temperatures in the northeast states could easily use over 100 amps. If you fill the bathtub, turn on the oven, and charge the car at the same time, you could trip your main breaker.