No, you'd don't need net metering to make it viable.
In a typical grid-tied system, the setup is such that any demand is fulfilled first by solar capacity, and second from the grid. If your array can fulfill 100% (or more) of your demand, then you pull nothing from the grid.
If you don't have a net metering arrangement and you regularly produce more than 100% of your local demand, then your options are to simply throw away the excess, or use a battery system to store it for later use.
If you have a net metering agreement, then the grid acts like a giant battery, which may or may not have input and output fees (think of it very roughly like Amazon S3 pricing). Ideally you have a 1:1 arrangement, where you can feed energy into the grid for free, and pull back up to whatever you supplied at parity pricing (eg: for free). But, there is no reason a utility company has to offer that arrangement, they could charge you some fee to supply energy if they wanted, and they could charge you some fee to pull energy back.
For the most part, the most cost effective solar systems will supply about 75-80% of your average monthly demand. It almost never a good investment to overbuild your solar system on the premise of making money off of net metering, as the rate you are paid for production is essentially a wholesale price, making you a micro power plant, which is not a very profitable business. Covering the bulk of your energy usage with your own solar supply, and then pulling a minimum amount of power from the grid to fill the gaps will tend to keep you at the best supply pricing tier.
>… the most cost effective solar systems will supply about 75-80% of your average monthly demand
I am not so sure that is true. Seemingly a large percentage of new installation costs are fixed (paperwork, labor, inverters, etc) with only a smaller portion for the panels themselves. For a minor incremental cost, you can fully provision your house.
In a typical grid-tied system, the setup is such that any demand is fulfilled first by solar capacity, and second from the grid. If your array can fulfill 100% (or more) of your demand, then you pull nothing from the grid.
If you don't have a net metering arrangement and you regularly produce more than 100% of your local demand, then your options are to simply throw away the excess, or use a battery system to store it for later use.
If you have a net metering agreement, then the grid acts like a giant battery, which may or may not have input and output fees (think of it very roughly like Amazon S3 pricing). Ideally you have a 1:1 arrangement, where you can feed energy into the grid for free, and pull back up to whatever you supplied at parity pricing (eg: for free). But, there is no reason a utility company has to offer that arrangement, they could charge you some fee to supply energy if they wanted, and they could charge you some fee to pull energy back.
For the most part, the most cost effective solar systems will supply about 75-80% of your average monthly demand. It almost never a good investment to overbuild your solar system on the premise of making money off of net metering, as the rate you are paid for production is essentially a wholesale price, making you a micro power plant, which is not a very profitable business. Covering the bulk of your energy usage with your own solar supply, and then pulling a minimum amount of power from the grid to fill the gaps will tend to keep you at the best supply pricing tier.