My current annual electric power usage is 1718 KWh; monthly average is between 120 Kw (winter) and 200 Kw (summer - due to AC and increased use of the washing machine). The apartment has been built in 1993 and I got a tax bonus in 2010-2011 to refurbish it with energy efficient
technologies. I will recover up to 55% of the cost as income tax deductions, on the next 10 years;t The market value of the house also increased.
There is a 5cm thick additional insulation layer on the outside of all perimetral walls and on the top ceiling.
All Windows glass is double pane.
A condensing boiler (natural gas powered) provides central heating and hot water.
The ducted air conditioner is a high-efficiency Mitsubishi inverter (made in Japan), I turn it on in july-august to reduce the heat but I don't use it as heating unit because the condensing boiler has a higher efficiency. It only draws 1.8 Kw, so I can use it on my 3 KW standard residential power supply and still have one major appliance running at the same time.
Refrigerator and fridge are separate units, so each one is optimized for the task and efficiency is higher. Both are smaller than normal, because there is a supermarket in walking distance and I don't need to stockpile; this also helps avoiding overeating. It was difficult to find a refrigerator and a freezer so small, and they cost more than regular size units, but they draw very little power.
Lighting is LED and fluorescent.
And... the power hungry home servers are off and kept in storage, replaced by a single low-power HP microserver (turned off when I don't need it) and several cheap VPS and dedicated, rented as needed. Due to my job, I could grab almost for free and run at home heaps of 7-8 years old retired servers, and I was doing so years ago. It became clear that this was not a productive use of time, space and electric power.