Yes, you can. For residential, the maximum size is 12kW for single-phase and 72kW for 3-phase. However, if you install more than your house consumption, you may run into the risk of not utilizing your credit and after 24 months, the credit (i.e. the amount of ringgit TNB owes you) will be forfeited. Therefore, it is advisable to install based on your consumption level. Read more about this from the SEDA website www.seda.gov.my