Tag: Time-Of-Use

What Is Griddy?

Griddy offers a retail electricity plan indexed to the real-time wholesale (or “spot”) price, which updates every 5 minutes per supply and demand. Unlike traditional plans, Griddy does not guarantee a fixed rate over a contract term. Instead, they take a lower overhead approach where customers assume the pricing risks of full spot market exposure. Since there’s no guaranteed rate, there’s no contract term or early cancellation fees.

Griddy charges a $9.⁹⁹/month membership fee, then passes through all other costs without markup for every 15-minute service interval. Service is prepaid similar to a toll road account. $49 opens your account, which recharges automatically from your debit or credit card when the balance drops to $25.

Griddy is a great option for some users, but it isn’t for everyone. Electricity spot markets are highly volatile, and most consumers don’t understand the risks and effort involved. Prices are low most of the time, but can quickly spike to levels that break household budgets. Just ask anyone on Griddy in August 2019 when the spot rate jumped from 3 ¢/kWh to 900 ¢/kWh for hours. Many who didn’t reduce their usage paid hundreds of dollars for a single day.

The tradeoff is one of reward vs. risk management. Whereas fixed-rate contracts insure the customer against rate changes, Griddy users are “self-insured”. And with self-insurance, you must have the financial means to absorb high prices, take actions to mitigate them, or both. But is the reward worth it?

Savings Claims

Griddy often touts savings versus the Texas average, but that’s a weak benchmark. The average Texan pays a woefully high 11.7 ¢/kWh, mainly due to expired or tricky plans. For those that neglect their utilities, Griddy may indeed save them money. But so would 10 minutes of shopping.

A better comparison is between Griddy and competitive fixed-rate plans. Griddy stakes a claim here, too, asserting that “Real-time rates beat fixed-rate plans every time.”¹ They don’t, however, offer any supporting data. So we opted to do the math and sign up for Griddy to sample their service for ourselves.

For transparent comparison, we created the internet’s only Time-of-Use Plans spreadsheet calculator, posted here. Plug in your electricity usage history from SmartMeterTexas.com to compare your 12-month average Griddy rate to the best 12-month fixed rate available at the same start time. Since spot pricing is too volatile to forecast, the Griddy plot lags by 12 months. Comparing over 12 months is key, since electricity pricing varies by season.

Historical Performance

For an average usage, Griddy generally hasn’t beaten the best fixed rate plans. An exception was June 2018, when shortage fears drove fixed rates especially high.

How can this be, if “every REP [Retail Electricity Provider] purchases their electricity from the same price, the real-time wholesale price”², and Griddy uniquely “cuts out all the needless layers…to keep costs low”³? Some reasons:

• REPs do buy “wholesale”, but not only on the volatile spot market. Other wholesale forward markets cover from one day to years in advance of delivery. To offer low fixed rates that also insulate customers from the spot market, “layers” of employees constantly shop to secure capacity at attractive prices.
• Griddy’s $9.⁹⁹/month membership fee adds ~0.7 ¢/kWh for the average home, or less for homes with higher usage.
• Griddy downplays ‘Ancillary Services’ charges, which add 17 – 36% atop the spot price on the bills we’ve seen. Exact rates aren’t publicly disclosed, so our calculator assumes 20%.
• Griddy passes through a 2.5%+25¢ fee for each credit or debit payment. To avoid credit checks and customer defaults, Griddy is prepaid only. But they don’t support free bank drafts like most REPs.

Price Spikes

Last but definitely not least is spot market volatility, aka “price spikes”. The spot market works like a real-time auction, balancing electricity supply vs. demand for every 5 minute interval. As supply gets tighter, prices go up. When it gets very tight, they go up a lot. Sometimes spikes follow predictable events like extreme weather. Other times, a generator or transmission line failure causes issues out of the blue.

The chart above shows the impact of August 2019 spot price spikes on an average Houston home. Two days at ~200 ¢/kWh — including four hours at 900 ¢/kWh — raised the 12-month average rate ~2.5 ¢/kWh, or ~$350/year.

Griddy notes that >$1/kWh spikes are less common than “negative” (<$0/kWh) pricing, which is true. But the magnitude of these spikes, multiplied by the higher usage that drives them, can do sizable damage to electric bills. And while negative energy prices are nice, they rarely go negative enough to offset the TDU delivery charges. So don’t expect to make money running your arc welder at 2:00 am.

Shift and Save

Getting the best price on Griddy requires using less electricity when prices are high. In Texas, that typically means hot summer afternoons from 2 PM to 6 PM when millions of air conditioners are running full blast. Occasionally it’s cold winter mornings from 6 AM to 8 AM. When prices spike, Griddy users are financially motivated to shed or defer as much discretionary load as possible. Air conditioners, heaters, dryers, ovens, electric vehicles, and pool pumps are the first priorities.

How much can you save? That depends on you. The typical Texas usage profile would have cost ~5.4 ¢/kWh plus delivery over 12 months. The key exception is the 12 months prior to August 2019, when the average spiked to ~8 ¢/kWh.

But what if that same home had deferred 50% of their load whenever prices exceeded 10 ¢/kWh (~2% of the time)? Per the orange line, they’d normally have averaged ~4.8 ¢/kWh, or ~6 ¢/kWh leading up to August 2019. That’s good enough to beat the best fixed rates from Sept 2019 onward. Granted, 2020 didn’t have summer price spikes like 2019 due to COVID-19.

Finally, the pink line shows the incremental savings for a home that averages 2 MWh/month instead of 1. In that case, Griddy’s $9.99/month fee contributes 0.5 ¢/kWh less.

The ability to lower your costs by changing your consumption behavior is Griddy’s main benefit. With a fixed rate, your rate is based on the projected average behavior of all customers. Wholesale plans, however, reward individual efforts to defer usage when prices are high.

Non-Trivial Effort

Shifting your usage takes effort, but Griddy provides tools to help, starting with an excellent app. On your phone or PC, Griddy shows real-time and projected spot prices through the next day. You can slice and dice your past usage, rates, and costs for any timeframe to easily see and learn from usage and price trends.

The app also alerts you to price spikes in real time, so you can you can turn devices off if you choose. The alerts work as intended, but they are not a long-term solution. Manually responding to repeated alerts disrupts daily activities. And when work or life prevent a timely response, alerts can be downright stressful.

Automation

A more convenient and effective approach is to use home automation. As a first pass, nearly every load listed above can be scheduled with a programmable thermostat or timer to avoid the typical peak hours. This approach too has limits: Shutting off the AC for 4 hours every summer afternoon can impact family dynamics, to say the least.

For better results, Griddy enables event-driven control through IFTTT. IFTTT is a freemium service for implementing simple “If [This], Then [That]” rules. Griddy shares their spot price feed on IFTTT.com, and many appliance manufacturers allow IFTTT-based control. Between the two, users with an internet-connected smart thermostat can specify “If electricity prices exceed 10 ¢/kWh, then raise the AC setpoint 3°F”, or “If electricity prices return to normal, then resume the programmed schedule”. That way, loads are disabled only if/when prices actually spike, which is much less disruptive.

In practice, we experienced IFTTT reliability and response lag issues during the August ’19 price spikes, but Griddy says they’ve since worked with IFTTT to fix them. We also had to set the thermostat to pre-cool our home an extra 2°F from 11 AM to 4 PM so it would stay tolerable even if IFTTT disabled the AC for several hours. IFTTT supports numerous smart thermostat brands. They do not directly support any pool or EV charger brands, although some workarounds exist.

Greener Than Most

For clean energy supporters, Griddy is a compelling choice, but not for the reasons most people expect.

Unlike other retailers, Griddy doesn’t tout “100% renewable” energy backed by Renewable Energy Certificates (RECs), and that’s good. RECs don’t motivate new generation projects, they’re often overpriced, and they give consumers a false sense of accomplishment. Selling plans in Texas backed solely by REC purchases is essentially greenwashing.

Instead, Griddy educates consumers how they use electricity and financially motivates them to reduce or shift their usage. How is that “green”? As overall demand ramps up, grid operators tap resources from lowest to highest cost (and, as it happens, emissions): First wind and solar, then natural gas, and finally coal. Griddy’s price alerts often indicate expensive and dirty coal plants are ramping up to meet demand. But if enough consumers defer their load in response, those plants will stay offline, and the load will eventually be served by relatively cleaner natural gas plants instead. By changing their consumption behavior, Griddy users save money and incentivize a cleaner energy mix.

Of course, you could opt to behave the same way on a fixed rate plan, but would you? Like any insurance, fixed-rate plans decouple behavior from immediate consequences. Consumers feel free to consume, knowing someone else (the REP) is absorbing the impact of peak pricing. Not with Griddy: There’s nothing like a 200 ¢/kWh day to influence how and when you use energy!

Solar and battery storage owners may also benefit from Griddy. These technologies inherently reduce grid consumption during peak demand hours. And for excess generation in any 15-minute interval, Griddy credits customers at the spot rate for energy (but not TDU delivery). Whether Griddy offers the best payback for your system depends on a number of factors, so plug your data into our calculator or get a free, unbiased analysis.

Summary

Direct exposure to spot market prices is risky business. Griddy is leading efforts to bring it to the mainstream, but it’s not for everyone. Scoring low prices takes considerable effort to avoid price spikes, though some folks (like us) may enjoy the challenge.

At a minimum, anyone considering Griddy needs enough cash reserves to buffer highly volatile summer bills. Beyond that, actually saving money with Griddy depends on your circumstances.

If you chronically neglect your electric plan as your retailer ratchets your rate upwards of 12 ¢/kWh, then Griddy may cost you less. But that’s a very low bar that hopefully doesn’t apply to those who’ve read this far!

If you regularly shop your plan, Griddy might still save you money if…

• Fixed rate offers are relatively high, and
• Your usage is relatively high, to dilute Griddy’s $9.⁹⁹/mo fee, and
• You use home automation to reduce usage during price spikes, or
• You have an inherently “off-peak ” electricity usage profile (e.g. rooftop solar, or multiple EVs charged overnight).

Everyone’s situation is different, and nobody can predict future spot market prices. Check out TPG’s Time-of-Use Plans Calculator to compare past Griddy performance for your home. Then click here to find your current best fixed rate.

 

Last updated: 9/25/2020