Yakub Ansari
- Sep 15, 2021
- 3 min read

Grid ties solar without a permit -Payperwatt

Grid ties solar inverters required grid power as a reference power source. And under the conditions of low power requirement and high power generation. It backfeed the excess power to the grid. Solar power need permits from utility companies to backfeed this excess power. Getting a permit is time-consuming and comes with a high price too.

What is grid ties without a permit?

To backfeed the excess power generated from grid-tie solar power plants, plant owners required permits from utility companies along with the net meters. With ZED Advance solar plant owners can eliminate this surplus power generation. And enable plant owners to run grid ties solar without a permit.

Permits are required only if you are backfeeding power to the grid by any means. But if you are not backfeeding to the grid, there are no permits required from the utility company. The problem with backfeeding power to gird is that it requires the load on the generators of the power plants.

And if more and more people backfeed power to the grid the daytime load on power plants will reduce drastically.

This reduction in power demand reduces the efficiency of the generators because generators give high efficiency at peak loads. Hence utility companies control this backfeeding of power to the grid by limiting the capacity of solar power plants connected with the grid.

But you might need other permits like building and fire permits to install a grid-tie solar power plant.

How to connect ZED Advance with a grid-tied inverter?

To install ZED Advance with your grid ties solar power plant, you will need CT(,s) before the electrical coupling point of the home meter and grid. And connect this (these) CT(‘s) with the ZED Advance via multiple core cable. Also, you will require an AC power source to power ZED Advance.

At last one LAN cable is required to connect ZED advance with grid ties inverter as well as with internet. Refer to the below image showing the typical diagram of connection ZED Advance with grid ties solar power plant.

Curious about ZED Advance? Click here to learn more

With ZED Advance you can also use the generator as a reference power source to run your grid ties solar power plant during a power outage. Refer to the below image showing the typical connection of ZED Advance with Generator and Grid.

As shown in the above picture you will require a transfer switch to switch the power source between generator and grid. You can use both manual and automated change over switches. Also, you will require an additional CT(,s) at the electrical coupling point of the generator and home load.

Learn more about Generator and Grid-tie solar synchronization systems .

How does ZED Advance work?

ZED Advance measure the load requirement from the CT and compare this information with power generated from the solar power plant if the generated power is higher than the load requirement.

Then it will command solar inverter via LAN cable to ramp down the power generation until solar power generation becomes equal to or less than the connected load.

Example:

Let’s take an example of a 100kW grid-tied solar power plant and ZED Advance is connected with it to control its power generation.

Now there are two possible cases, 1) load varies while solar power generation is constant and 2) Solar power varies and load remain constant

Case#1

Let’s take a case when the load is varied and ZED Advance control the output power of the Solar (on-grid) Inverter as per the load.

In the below case, the PV plant can produce 100kW of power and the load varies, but ZED controls the output power of the Inverter so that there is no surplus power hence the plant can run without net-metering.

Case#2

In this case output power of the PV plant varies and you can see how the load is shared between the PV plant & Gird.

In the above GIF, you can see how the load is shared between solar and the grid.

Which inverters are compatible with ZED Advance?

ZED advance is compatible with all the major make of solar inverters.

And it can also be programmed for any other make solar inverter not mentioned above. All we need is MODBUS mapping of the inverter. Contact us with your requirement.