I hooked our solar setup several months after we moved into the house.
At first, I had the power going in directly into the breaker box. Once I was ready, I switched that over to the inverter & from the inverter back into the breaker box.
You can always add the solar at a later time as long as you plan for it ;)
One of the first things to familiarize yourself with is the types of solar setups (off-grid, grid-tied, grid tied with battery backup, grid fallback). Our setup is classified as a grid tied with battery backup (we are not set up to sell power back to the grid).
During the winter months, the sun does not visit enough for us to rely on our solar exclusively here in the greater Seattle area. On the other hand, when it’s sunny, we are almost exclusively off-grid. In 2014 for instance, we got all but about 4 days of our power needs from solar mid-April through early November!
For more details on our specific solar setup, take a glance at a blog post I did a while back & let me know if you have further specific questions on it. FYI, we purchased an inverter that cost quite a bit more and can handle around 10 more solar panels than we currently have, giving us the opportunity to add more panels later. Be aware that batteries cannot be added later as combining new batteries with old ones will shorten the life of the new ones to match the older ones :o
I wish I had an easy answer for all of your energy related questions…Unfortunately, it is not an easy thing to figure out. We ended up going through Whidbey Sun and Wind to assist with sizing our system. Also, some solar equipment manufacturers do not sell retail meaning you have to go through someone to order your system.
One of the most important things you need to figure out is how much electricity you currently use. You can do this one of many ways…you could grab your current monthly utility bills & subtract how much you are using in your current living situation that would not be brought into a tiny home (i.e. furnace, massive hot water heater, etc.). The other (and more accurate method) would be to use a solar sizing spreadsheet to calculate the power consumption of each of the specific items you plan to use (computer(s), monitor(s), hard drives, hot water heater, heater, fridge, tv etc.). Be honest with yourself…list everything! Even your hair dryer / straightener…even if you only use it for 2 minutes per day, it may require a huge amount of power! All of your appliances should list how much power they consume on them. If you have 2 of the 3 (volts, watts, amps), you can figure out the missing one. Most appliances list the Volts & Watts on them A = W / V or W = A × V
Once you have each of these items listed, you need to come up with a realistic number of hours that you use each of these items to calculate daily usage (be honest with yourself on this ;).
Once you have your power consumption figured out, you need to plug that all into a solar sizing spreadsheet & figure out how large of a system you need based on your geographic location (sun-hours/day).
Here is a good resource to check out: http://energy.gov/energysaver/articles/estimating-appliance-and-home-electronic-energy-use
I would definitely recommend you consider your appliances carefully if you want to be off-grid completely. You can find on-demand hot water heaters that use propane. You can also find propane refrigerators. By wiring our 4-gallon hot water into a switch, we leave it turned off when not in use. We also take military-style showers (water on long enough to get wet…back off…soap up…rinse off…done). This in conjunction with our low-flow shower head saves oodles of unnecessary power to heat water.
Hope this helps! Feel free to post in the comments section below & I will do my best to get any questions answered.