The question of whether there is cross subsidy of solar houses from those without is a complex one. Access to the electricity grid is a public good, in the same way that a road provides access to all (despite the fact that some drive more than others). There are many imbalances in how much reliance on the grid individual households have including air conditioning use at peak times, distance from infrastructure and in some cases whether or not you have solar.
Overall equity will be an important consideration in any business model explored. The cost of funding solar PV up front is prohibitive for some people. There are however funding mechanisms that exist and can be further explored through the development of the blue print and business case that can allow low income earners to participate, such as leasing to buy (where you lease out your roof and own the system after approximately 10 years).
It depends. How much we pay is driven by both the unit cost and how much we use. The current unit cost of electricity supply is made up of the cost to produce (generation), the cost to transport (network costs that cover transmission and distribution) and the cost to service (retail). While renewable energy may in cases have higher generation costs these are continuing to reduce dramatically and the global market grows. Renewable energy also has the potential to avoid transport and retail costs eg. solar on our roof means we offset the need to pay network costs for the energy we use onsite. How much we use is also key, increasing our efficiency means that we can use less and take control of our costs. ZNET is focusing investigation on options which are cost competitive with existing energy sources.