Household budget spreadsheet

The household budget spreadsheet is available here.
Tools to help you calculate out your CO2, and off-grid component requirements can be found here.

The household budget spreadsheet shows the figures for a regular, 25+ year old, family house (4 people) in a central european country. It should be treated as an example, and can be used as a template for others to fill in their own data, and draw their own conclusions thereof (often, things will vary widely depending on the country, and even in a same country, figures can differ a lot depending on the company supplying you.

Clear from the spreadsheet, the fixed fees (subscriptions) are not large at all in comparison to the price per m³ of water, gas, kWh of electricity, ... In countries however where energy, water, ... companies do request high fees, resource conservation via implementing green retrofits in existing houses will never quite take on as the costs of the retrofits are much higher than the economic savings you can actually achieve with them. Even in countries where the fixed fees are not large in comparison to the price per m³ of water, gas, kWh of electricity, ... (as is the case of the family described in the spreadsheet), green retrofits can still cost quite a lot in relation to the expenses you can save with them. In most cases, it will take many years to recover the money spend.

Also, in cases where  the fixed fees (subscriptions) are very large at all in comparison to the price per kWh of electricity, water, ..., going off-grid for power and/or water can be much cheaper than remaining a customer with the power/water company (as you then no longer need to pay the huge subscription costs). It should be noted that whereas you can cancel your subscription , you may obviously still wish to remain physically connected to at least the neighbourhood water/sewerage, ... system (as disconnecting physically would cost money). You would just no longer use it. For power, a complete disconnect could be advisable then though (as that would simplify the system, and protect you from say lightning strikes on the power grid).

Going off-grid for power can be achieved in practice by installing an energy storage system (preferably nickel iron batteries, or alternatively industrial deep cycle batteries; don't use any other types as others typically don't last very long, and are much less ecological). Besides the possible avoidance of fixed fees, the battery pack will allow you to save some money as you can set it to recharge during off-peak hours (this could save you somewhere between 10 and 50 euro). In addition to the energy storage system, you obviously also need a way to recharge your batteries, which can be done by a renewable energy source; for example:
* PV panels (which you might all ready own)
* small-scale wind turbine
* microhydro power plant
* biofuel-powered internal combustion engine with attached alternator or dynamo; note that an internal combustion engine can also be used to heat your water (ie for showering, ...).

It should also be noted that setting-up a truly off-grid system (by combining an energy storage system with a renewable energy plant and also disconnect the connection to the mains electricity grid) won't allow you to supply back any power to the mains electricity grid via net metering. As such, this setup would be less ecologic than a grid-tied system in which you are able to sent back power to the grid. Economically seen though, even by sending back power (and getting paid for this), the solution might still be less financially rewarding than setting up a grid-tied system with net metering. This because, in the event it isn't (say if the power company does not charge hefty fixed fees), you probably wouldn't set up an grid-tied system with net metering anyway as the purchase costs of this equipment would again outweigh the costs of just buying power directly from the energy company.

Going off-grid for water can be achieved by installing a rainwater tank, and having the water from your gutters/rainwater piping connecting to it and (if you want to have it immediately available to your taps, toilet cistern, ...), also add in a pump, and a pressure vessel. The pump can be run from your off-grid energy storage system (if you added that as well).

It should be pointed out however that depending on the country you are in, not only the fixed fees and price per m³ of water, gas, kWh of electricity, ... can differ, but there may also be national programs in place that financially help compensate or even tip over the balance into the right direction. One word of warning though, besides the fact that these may or may not be present, there are often many conditions your equipment needs to adhere to (for example, minimum size of the PV panel array, ...)

Also, the way on how you install and combine the water heating, energy, ... systems in your house can vary greatly.

For example, installing PV panels or solar thermal collectors in a central european country, on a steep roof pointed towards the north will mean the efficiency of the panels will be rather bad in comparison to what they could be when installed correctly (for example, at a flat roof, at the optimal inclination, towards the south).

Also, solar thermal collectors will obviously work much better in hotter countries than in colder countries. Depending on the type of solar thermal collector you own, it may be better to diconnect the power to the pump during winter as it will not improve heating of the boiler during that time (rather it will then cool it).

Another thing to consider is the type of systems you use which also affect performance. Depending on how you use the devices, the type of device may btw also be more or less efficient. For example, you can buy a water heater with a tank or a tankless one, you can have these heated using a fuel/gas or using electricity, if you use one with a tank, you can attach it to a solar thermal collector, ... People that use it every day for showering may be better off with say a version with a tank, and solar thermal collector. Those that don't use it much at all, could prove better off with a tankless one, ... 

Finally, in older houses, older equipment may be present, which still works, but which might not be (well) compatible with "new developments" like net metering, ... For example, in the past (very old houses, say well over 30 years old), single tariff meters were the norm, whereas today, multiple tariff meters are being used. It seems but a trivial thing, but not if you need to buy this yourself (rather than say having it being part of the service ordered and offered by the electrical company). If you need to buy this, you'll find that the purchase cost can be dozens of times the price you might save with the economic gain you can have of say drawing power during off-peak hours (say 100 to 400 euro for the meter installation). It should be noted here however, that most often the meters are rented instead (not bought), so in that case you could just stop paying the rent for that meter and rent another (multiple tariff) one. Off-peak hours are from say 22:00 hr to 07:00 hr. In case you're wondering: no you often can't set your single tariff meter to off-peak hours; it's normally set instead to peak hours.

All in all though, you should generally not see it as an investment that can be recovered, as in many cases, it could just cost you money instead. That said, even if it's economically perhaps not rewarding (again, depends on the country you're in, and what retrofits you actually implement), it does have some other benefits that can't be overlooked; for instance:
* self-sufficiency (you're no longer dependant on any company for your basic necessities like water, power, ...); as a result, power outtages, water cutoffs, ... no longer affects your household
* no risk of  damage or health problems caused by improper management of the companies that otherwise supply you; for example lightning strikes on the power grid can cause many of your appliances to become damaged beyond repair, water contamination of the water grid could cause health problems, ...
* reduction of the amount of carbon offsets you'd need to buy annually to offset your carbon footprint on the planet. Most people aren't offsetting their carbon footprint annually at all; however as natural disasters, caused directly to climate change, claims thousands of lives each year, not doing so actually makes you directly contributable in their passing. It should be noted here that even if you live in a country that has ratified the Kyoto protocol, energy suppliers still only compensate a part of their emissions, as they're allowed to emit a certain amount of carbon dioxide. The easiest way to calculate how much you need to compensate is by just adding up the amount of kWh you spend on heating your house, water, and driving your car (if you have one) and multiplying that by either 0,6 or 1 or 1,5 (0,6 kg in each kWh when using natural gas, see here, 1kg in each kWh when using coal,  and 1,5 when using wood, see here). Nuclear power needs to be multiplied by 0,006, hydroelectric by 0,004, wind power by 0,02, and PV solar panels by 0,10. If you use firewood, but replant it you won't need to calculate that in. The same goes for biofuels (straight vegetable oil, biobutanol, ethanol, ...) coming from crops that are continuously replanted, as well as biogas. Gasoline needs to be multiplied by 2,3 (2,3 kg CO²/liter, see here ) and diesel fuel needs to be multiplied by 2,6. The carbon emissions of the food you consume, the waste you generate, ... isn't added in as these are not really calculatable. The CO² emissions of the house construction itself too isn't added in as we're assuming you are retrofitting and existing house, and the emissions of the construction of that house would have occured a while back, meaning there is no retrievable data on it anymore to calculate the CO² emissions, and/or it may have been done by a previous owner, meaning you're not responsable for it. You can find a list of companies from which you can buy the CO² compensations in the "List of companies supplying VCU's and CER's" post.

If you don't want to spend a lot, and/or have a good financial compensation based on the money put in to the green retrofits, it would help to examine things carefully for your area and only implement those retrofits that offer the greatest savings/cost the least. For example, adding insulation to your roof and plugging holes in your house found with a blowerdoor test could prove quite rewarding/offer the most savings. This is mainly because by far the most energy (2,5 to 3x as much in fact) is lost due to improper heating of the house (see this wikipedia page).Also, again if you offset your annual co² emissions, it too will help the most to reduce the expenses of this.

For newer houses, you'd need to buy new equipment anyhow, and you also don't need to work with the existing infrastructure, meaning that in many cases, the installation can be made simpler/more effective (for example for rainwater harvesting, you could make your house so that you don't need much piping/pumps, ... but instead rely on gravity, ... more). Also, the added cost in relation to the expenses you'd need to do anyhow is comparitively much lower. So with new houses, the economics of implementing green features is often much more positive.