Solar Panels With or Without Battery? How to Make the Decision?

Want to go off-grid as well, have a solar battery backup system or merely increase your level of self-reliance? Well, your goal will impact the type of battery system you invest in. Energy Storage Systems [ESS] aren’t for everyone though, so here we look at the pros and cons of investing in an ESS.

Pros of Solar Power with Batteries

  1. Battery backup
    If you have a grid-tied solar PV system it produces clean energy during daylight hours to power your internal electrical appliances. Any excess power is fed back into the grid. However, should your utility experience an outage then you will be left in the dark—pardon the pun. Having a battery backup system incorporated into the design of your solar PV system will provide backup power for a limited amount of time.
    How much backup power you have though depends on how much power is being drawn from the battery system and for how long. This will also be impacted if it’s day or night as if it’s during the day any power demands will be supplemented by both the PV and battery system.
  2. Increased self-reliance
    Unfortunately, solar power only produces electricity during the day when we aren’t home. Most of the electricity we consume in our homes is in the evening. Having a slightly larger solar PV system will allow you to store the excess energy produced in the battery system for use later when you need it. A perfect example of this is in the evenings when your lights are on or you are cooking, using the dishwasher etc. This approach will also reduce the amount of electricity you draw from the grid and will reduce your electricity bill further.
  3. Load shifting
    The time of use (TOU) tariff quite commonly found in commercial or industrial facilities is increasingly becoming more mainstream for residential and commercial utility customers. The TOU tariff charges different kWh rates depending on the time of day and time of year. Typically kWh rates would be cheaper during the day and more expensive at night based on the fact that demand for electricity is higher during evening time. For big cities like Karachi, the peak tariff hours are usually from 6:00 pm to 11:00 pm. Load Shifting is the practice of moving energy consumption from peak tariff hours to either period of the day when the tariff is lower or moving the energy consumption to an alternative source. A good example of this is using energy stored in a battery system during peak tariff hours.
  4. Reduce your carbon footprint
    Most if not all utilities rely on fossil fuel to a certain extent to produce electricity. This means the CO2 emissions for the grid electricity you use will vary depending on the energy mix of the utility operating in the state you live in. Some states have higher grid CO2 emissions factors than others. Having a solar PV system with an energy storage system will reduce your carbon footprint significantly. MaxGreen aims to stand firm on our vision of Clean, Green, Smart Energy in Pakistan; you may read our other blogs to learn how to become a part of our vision.
  5. Become energy independent
    There’s something about going off-grid that brings a feeling of inspiration and freedom. Not relying on your local utility to provide power but generating your own clean electricity—100% of it. In the past, one would require a large battery bank to provide enough juice to power your house for when the sun ain’t shining. Nowadays though, with Lithium-ion battery technology, you no longer require a whole room dedicated to batteries. One does need quite a large solar PV system, however, to cater for all your electrical loads plus a bit extra to charge the battery system.

Cons of Solar Power with Batteries

As with everything in life, there are advantages and disadvantages. Let’s look at some of the disadvantages of implementing a Solar Battery System.

  1. High cost
    The cost of energy storage is quite high and can quite easily increase the cost of your solar PV system substantially. So it doesn’t always make financial sense to install an energy storage system—it really depends on your consumption tariff rate. Therefore it’s worth calculating what your return on investment would be if you had to invest in a solar battery system.
  2. Complexity
    Designing and installing an energy storage system increases the complexity of the solar PV system. This also means more things can go wrong, in both the design, installation and operation of the battery system. During the design phase, it’s crucial that the battery system is sized correctly for the requirements, and the right size cables and switches are installed. Solar battery systems also need to be located in a cool environment with adequate ventilation as they don’t like heat. The right type of environment or enough space might not always be available.
  3. Increased maintenance
    Whereas solar PV systems are relatively easy to maintain, including a battery system does increase maintenance requirements, although the level of maintenance depends on the type of battery technology you are using. With deep-cycle lead-acid batteries, the water levels need to be periodically topped up and the terminals kept clean. One can’t use normal water either—it must be distilled water. The chemicals in batteries are normally highly toxic and corrosive, so care also needs to be taken. However, other more modern types of energy storage batteries such as lithium-ion are generally maintenance-free.
  4. Lifespan
    This also depends on the type of solar battery being used and the level of battery discharge. Lead-acid batteries can only be discharged to a maximum of 50%. Discharging these types of batteries more than that decreases the lifespan of the batteries considerably. Lithium-ion batteries can be discharged up to 80% though. Expect to replace your battery system at least once during the lifespan of your solar PV system.

Conclusion

Deciding on whether to invest in an energy storage system is not an easy one. One really needs to do their homework and weigh up the pros and cons.

Is the extra expense worth it? If you are in an area that is prone to blackouts then it could be worth the extra investment.

Take into account the extra maintenance that might be required and if you have the right environment for storing your solar battery system. Also, be aware that you will more than likely have to replace the battery system at least once during the lifespan of your solar PV system.

If you are still confused in making the decision contact us to set a free consultation for your solar requirements.

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