All right, now that we've talked about storage in general, let's dive into batteries as an enabling technology for renewable energy, yep. >> The battery market can be divided up into two pieces to some degree. The utility scale and distributive batteries, utility scale means big batteries, basically those that go along or next to a full sized power plant of tens or hundreds of megawatts. And as we talked about in the tutorial storage basics discussion, there's a lot of things batteries can do, a lot of benefits batteries can provide. For example, utility scale batteries which we're talking about here can reduce curtailment because let's just say there's not left capacity on the transmission line. The battery can store the output and send it down the transmission line later when there is room. It can do firming which is let's imagine you have a solar photovoltaic, 100 megawatt power plant. But the clouds come over well, the output would go down except as you have batteries that are charged up they can fill in. And so the total combined kind of gross output of the combined storage plus the PV is is firm meaning it's there when you need it. And there's some other examples of what utility scale batteries can do. And as we just saw big batteries can be ameliorate or address the duck problem by getting charged up during the day when there's too much, not too much, but a lot of solar PV and discharging his night when you need more electricity. But there's another way batteries can be used which are sometimes called behind the meter or BTM batteries. So you can imagine in a house or industrial building, it could be a school, a hospital, office building that there's batteries along with say, a rooftop PV system. So the rooftop PV can work with the batteries. And both of these are what's called behind the meter or on the other side of electricity meter relative to the grid. So let me show how that might work and what are some of the advantage of that. Many large, most I would say larger buildings, not residences, but schools, hospitals, offices, pay something called the demand charge, which is if you look at the monthly electricity bill for most large buildings. The bill includes how much electricity the building used over the course of a month, as well as how much was used at any one time called the peak demand charge. Well, batteries can can reduce that. Here's how that would work. Imagine you have a battery system and this green line shows battery charge discharge. So the battery is being charged up and then imagine in the morning there's a peak demand of the building, which is the blue. But then the battery trims the peak off it's been charged up here and now discharges or an effect reduces the demand of the building, as seen from the grids perspective. Because the peak part of the building load is met by the building zone batteries and the same thing might apply in the afternoon, where the battery charges during the day and in the evening when the building is having its peak load. That peak load is met in part by the batteries. So the net effect of the batteries is to trim these peaks and these peaks can be very expensive. So the advantage of the batteries here is they can reduce electricity demand charges. So, it's just another example of the many benefits batteries can have, for electricity grids. And there's a lot of ways batteries can be used or applied. We talked about bulk storage or near the power plant and can be residential storage behind the meter, at a house and anywhere in between so called distributed storage, bulk storage. There's a lot of rules batteries can play or storage, general complaint electricity systems. Now focusing on batteries they're being implemented now there's not starting for relatively small base, annual growth and battery installations is quite high. And here's what they would actually look like. Here's the battery system where each individual bank of solar PV panels has a battery. Here's the battery system, at a transformer station and here's a schematic of what it might look like to combine the two. In fact if you have PV in storage, there's a lot of different ways you can wire it, but this is a typical way you have your floatable tax and you have your battery and then there's one connection to the grid. So the batteries plus the solar PV acts as a power plant that is firm or reliable as I mentioned before. Imagine you have your big photovoltaic plant and then the clouds roll in. Well, then the batteries kick in and the plant as a whole becomes a reliable firm output. Similarly, if you have PVP batteries, you can imagine a situation where the electricity grid or system needs electricity right after the sun sets, for example, in California. Well if the power plant operator know that's the situation they can use the photo text during the day to impart charge the batteries. So the combined power plant can actually continue to deliver electricity once the sun goes down. So that's a schematic or an understanding of how storage can be combined with utility scale PV. Now, if you actually look at what the batteries might look like, it's not just a battery itself, it's a whole system. Similar suitable tech are the module PD part itself. What's lots of other components wires physical frame structures to hold it up, inverters and so on. Batteries the same. You have the storage device, you have monitors and control switches, temperature control, power conversion systems, AC transformer to step up, the A C Voltage to what the grid requires and so on. So it's a whole system. Well, one of the reasons these systems have become such great interest is like wind and like solar PV utility scale batteries have seen dramatic cost decreases. Your stated from the US but it's comparable that worldwide costs have seen comparable decreases. And from these data utility scale battery utility scale battery storage cost decreased nearly 70% between in just three years. So this technology has seen very rapid price decreases relatively recently. Now it's not going to keep up that pace of decrease. But it's likely that costs will continue to come down. This we'll talk about in just a minute. So we'll take a quick break there and come back and talk about where batteries appear to be going.
