The local electricity utility generally provides power supplies. Although this is often highly reliable, the consequences of even very occasional failure mean that you should give high priority to the problem of reliability of supply.
Install uninterruptible power supply (UPS) as a fundamental aspect of ensuring high availability
UPS is relatively cheap and you should install it early on when building high availability into your SAP system.
Consider the following to protect your system from power supply problems:
You can take the following measures to cope with complete failure of supply:
Additionally, you can install a power conditioning system in areas where the power supply is reasonably reliable, but might be subject to significant fluctuations in current. Variants of UPS are available to protect the hardware against various power supply problems (for example, spikes, surge, sags, noise, brownouts, blackouts, and harmonic distortion).