Detail the advantages and disadvantages of integrating various renewable energy sources into national electrical grid systems. Focus on environmental impact, costs involved, and load balancing. Consider Solar PV, Wind, Hydro, and Biomass Electricity (including waste incineration) and any others of your choice.
Use case studies of proposed or implemented renewable installation to support your findings with any factors relating to specific local and/or global locations.
Provide references to support any scientific technological claims reported. You should include quantitative information to support your discussion and conclusions.

Maximum of 1100 words including references.