A Spore hit just drains too much health and power to be fun, especially if you are trying to build a base at the same time. With a 30-sec interval, you might get away with it, but you are currently requiring constant Shield micromanagement to allow for charging/repair, not counting the construction or operation cost.
Taking a Spore depletes a Shield of 47% health and 1/3 charge. 1/3 of 30 Packets storage is 10 packets, paid every five seconds. This is a serious energy drain, needing five Reactors just to keep up.
For health, the time for a Shield to regenerate after a Spore hit is 23-odd seconds. This will require five Shields taking hits in turn, assuming proper micromanagement.
Assuming that a dedicated CN is available to take most of the power load, two Reactors will give a tiny surplus, around 0.3 packets per second. This will run a single Shield on a one-fifth duty cycle. Your "disarm" command will be constantly used, as you advance frame-by frame to get the next Shield up in time, without using any unnecessary power.
The construction bill for this minimal setup is: 1 CN, 5 Shields, 2 Reactors, and initial charge for at least one Shield. Total: 505 packets (more than the cost of a Thor, though this setup is self-powering with the CN's help).
Without tapping the CN, you need an additional 150 packets for more Reactors, and you are precisely covering the recharging cost. More still is required to operate the Shields.
Fortunately, the load is constant, making the game progressively easier as more Shields and Reactors take the strain.
In my variant on this idea, published some time ago, a base was provided (for free), with several PZ Shields and enough power. It wasn't fun, even then.
2000 Creeper/Spore makes a single hit disastrous, nay fatal. The Creeper needs only to be lucky once. You must be lucky all the time, and be able to replace everything in the area of that Shield, and clean up the Creeper.
Setup
There is doubtless room for the setup, and a max-production Collector grid can gather a significant amount of power in the grace period. Deleting this grid when the Spore Tower is finished can save a lot of Creeper landing. However, a fresh Shield every ten seconds is required soon enough, though the first one can regenerate entirely by the time the fifth is unusable, given enough power.
Did I mention that all Shields must cover 100% of the base, or a few Spores at the wrong spot can kill you? You can sacrifice security for space by spreading them more thinly, but you need to look well in advance to know where to shuffle the Shields to.
Even a Forge would not help.