1. Believe it or not, you, your family and your neighbors aren’t the only consumers of electricity. We also have businesses, industry, schools, streetlights, trains etc.
2. Most buildings probably don’t have enough roof top area to produce all the electricity it needs anyway, let alone all of the energy our society need as a whole!
3. Most roofs don’t have the optimum direction/angle towards the sun and shading is a big issue. In a solar park, every panel will be installed in the optimum direction/angle and tracking can be added as well to utilize the solar panels to the maximum. The added electricity generation is easily enough to offset whatever is lost in transmission.
4. You can add hydro, wind and other energy sources to the energy mix.
5. It`s more cost effective to install solar panels in big solar parks.
6. It’s easier, safer and more cost effective to clean and maintain a solar park
7. It`s easier and more efficient to export electricity to pumped hydro plants
8. It`s easier and more efficient to export electricity to industrial sites
9. It`s easier and more efficient to export electricity to another city/region/country
10. Big grids with millions of consumers gives more potential for load shifting such as:
- charging cars while at work (noon)
- industrial shutdown during periods of low electricity generation (night & winter)
- tap water pressurization
11. Excess energy can be used for “more or less” productive things such as:
- produce hydrogen
- water desalination
- produce synthetic fuel
- remove CO2 from the atmosphere.
- reduce cooling water temperature for thermal power plants
To sum it up:: Big solar parks combined with a high capacity grid is a more flexible way to create and distribute renewable energy.
So no more solar rooftop? Not necessarily. But the vast majority of solar panels should in my opinion be installed in solar parks. If a house produce more energy than it consume or is able store in a battery, the solar system is to big.