![From the office…Information Gathering]()
by Synergy Solar | Jan 10, 2024 | Battery Storage Systems, Solar Installation
Considering solar or battery storage? There’s a lot to know. Also there is a lot of information to gather. Here at Synergy we are going to ask you a lot of questions, and sometimes you might think we are being nosy, but the more we know about your electrical consumption habits, the better job we can do at designing a system that will serve you best. Sure, we could cookie-cutter it over the phone and guess your roofline off the internet and use averages to suggest a system, but this is not our way.
Yup, I’m a lefty.
Here at Synergy it all starts with a series of questions about what your goals are, the physical setting of your property and, especially for back-up batteries, what kinds of consumption (or loads) you have that might be significant. (A well pump is a common one. When a well kicks in it can draw LOTS of power to get going, just like that first pedal to get a bicycle going.)
We are also going to ask you to download some data from PG&E. There are data files of not just how much power you use, but when you use it. Using power midday is different than using power at sundown when the solar is not producing. This also might vary in different seasons. In the most common cases, a battery system to store your excess production for use after sundown is the most important part of your system to reduce your bill and improve the return on your investment. Gathering your PG&E data helps the design process.
We are also going to need to know things like who the actual property owner is and who is listed on the PG&E bill to make sure we get the right names on the right documents and things move along smoothly. During the installation process we will be applying to the county (or city) for permission to safely install, and to the utility for permission to operate your solar system. These steps often feel like irritating hoops to jump through, but they are designed to maintain the safety of the community.
Each application requires consumer protection documents showing that the property owner is clear on the costs (thanks to some nefarious folks out there) and agrees to the installation, how the install will affect the power grid, and that the system is electrically installed safely (no fires, please). One example of safety requirements are fire regulations to leave room for fire fighters to move around on a rooftop. On rare occasions, PG&E will require other safety changes before the installation is approved. In my case, it was necessary to install a new power pole to properly support lines (no fires please).
Once Synergy has completed the installation, the county (or city) will check our work and approve the permit. (I have to throw out that our team is stellar and regularly sail through these inspections with no issues. They do an awesome job.) With the approved or “finaled” permit, we can then complete the application to the utility for the permission to operate or “PTO”.
When we get the PTO, we commission the system and turn it on. Finally, we let you know that you can view the system in action on the Enlighten app and assist you to set that up if needed. Yup, it’s a lot of steps and requires lots of information and documentation beyond the physical installation, but we carefully follow the process from beginning to end and will provide you with copies of all the essential papers.
We want to make our information gathering process as easy as possible, and suitable to your needs. In return we strive to openly provide you with information and answer all your questions!
by Justin Hiner | Sep 20, 2023 | Battery Storage Systems, Sonnen System Overviews
A Comprehensive Guide to Testing Your Sonnen Home Battery System
In the modern world, where energy sustainability and self-sufficiency are gaining importance, home battery systems like Sonnen have become popular choices for homeowners. These systems store surplus energy generated from renewable sources, such as solar panels, to be used when the cost of power is high and to provide you with a dependable backup power source during outages. However, like any technology, it’s essential to understand how to test and maintain your Sonnen home battery system to ensure optimal performance and longevity.
Why Test Your Sonnen Home Battery System?
Testing your Sonnen home battery system is crucial for several reasons:
Performance Verification: Regular testing ensures that your battery system is operating as intended, storing, and releasing energy efficiently.
Early Issue Detection: Testing can help identify any potential issues before they escalate, allowing for timely maintenance and preventing system downtime.
Optimal Utilization: By understanding how to monitor and manage your battery system, you can make the most of the energy it stores, leading to potential cost savings.
Steps to Test Your Sonnen Home Battery System:
- Safety First
Before you start, make sure to follow safety precautions. Familiarize yourself with your Sonnen user manual and locate the emergency shut-off switch in case you need to stop the test.
- Verify Battery Charge:
Ensure that your Sonnen system has enough charge to perform the test. It’s recommended to have at least 50% battery charge before testing. You can check the battery charge level through the screen on the Sonnen unit, on the Sonnen online portal or the Sonnen smartphone app.
- Familiarize Yourself with the Sonnen unit: Your Sonnen home battery system has a few ways to change settings as well as how to interact with the battery. It is good to look through your owner’s manual and know how they all work and when to make changes for the best experience during outages. Spend some time getting acquainted with the interface and its various features.
- Check System Status: Regularly check the system status on the homeowner app. Look for any abnormal readings during or before you test the system. This can give you an early indication of any potential issues that might come up during a power outage or while you are testing the system.
- Monitor Energy Flow: Observe how energy flows into and out of the battery system. During sunny days, your solar panels should be charging the battery. Take note of the energy stored and discharged.
- To Preform a load test, you need to simulate a Power Outage: you will need to intentionally disconnect from the grid and run some of your essential home loads on battery power. This test assesses the battery’s capacity to supply energy during an outage. There are two methods to test your Sonnen home battery.
a) The first option involves switching off the main electrical supply to your home, mimicking an actual outage and activating your battery backup system. To do this, locate your main circuit breaker panel and turn off the main breaker for the property.
b) The second option is applicable if you have additional circuits that should remain powered during the test (e.g., rental properties, electric vehicle chargers, hot tubs, or pool pumps). When conducting this variation of the test, locate the main circuit breaker for the Sonnen battery unit itself and turn it off while keeping the rest of the breakers on. It’s important to note that with this testing method, you won’t be able to determine which circuits are on the backup system.
- Time-Based Tests: Try running your home on battery power for various durations—30 minutes, an hour, or longer. Synergy suggests conducting this test for a complete day or for as long as possible to fully immerse yourself in the experience of using and interacting with the Sonnen system. This can help you gauge how long the battery can sustain your energy needs. As well as show you what things you may need to limit during outages.
- Watch for Trends: Over time, monitor patterns in your energy consumption, solar production, and battery usage. This can help you optimize your energy usage and identify irregularities.
- Seasonal Considerations: Test your system’s performance during different seasons. Solar energy production and energy consumption can vary, so understanding these patterns ensures year-round reliability.
Conclusion:
Testing your Sonnen home battery system isn’t just a one-time task; it’s an ongoing process to ensure its efficiency and longevity. By regularly monitoring your system, understanding its performance, and being prepared to troubleshoot minor issues, you can rely on your Sonnen home battery system to provide clean and reliable energy whenever you need it. Embracing this proactive approach not only benefits you as a homeowner but also contributes to a greener and more sustainable future. The primary advantage of testing your system while the utility grid is still operational is the capability to easily reconnect to it in the event of any issues.
by Mike Pane | Sep 5, 2023 | Battery Storage Systems, Solar Installation, Solar News, Uncategorized
Leading the Move to Energy Storage
Synergy leads the industry in solar battery systems and has installed them for over a decade. We stay ahead by adopting new battery technology as it develops. Batteries provide so much value that we stopped installing solar without storage in 2019. We still make rare exceptions, but storage has become the standard for most projects. This shift reflects rising utility rates, new tariffs, and the growing need for energy resilience. Synergy’s experience helps homeowners choose systems that fit their goals and protect their investment.
Utility Tariffs
Utilities use tariffs to determine how they credit exported solar power. The first tariff was NEM1 and the second was NEM2. New customers now use the Net Billing Tariff, called NBT. Homeowners who lose their original NEM status also move to NBT. These changing tariffs strongly affect solar savings. Batteries help reduce the impact of lower export rates under newer tariff structures. Understanding these rules helps homeowners make better decisions about storage.
Two Fundamental Designs
Battery systems follow two main designs and each design supports different goals. A backup battery powers selected loads when the grid fails. A savings battery stores excess solar and lowers your bill. Savings batteries discharge during expensive peak periods and at night. Under NEM1 and NEM2, savings were modest. Under NBT, savings batteries have become essential. They increase bill offset and shorten payback. A backup system under NBT needs a larger battery to handle outages and self-consumption. You can add backup ability later without changing your NEM or NBT status.
Understanding Battery Sizing
Battery sizing uses two ratings: kW and kWh. kW measures how much power a battery can deliver at once. kWh measures how long the battery can deliver that power. These ratings guide proper design choices. If you want more detail, we created a separate blog that explains these units that you can read here. Reviewing those basics can help you better understand the designs below.
Backup Battery Design
A backup battery system powers key loads during a grid outage. This design usually needs more equipment and a larger battery. It uses a transfer switch to isolate your home from the grid during outages. This protects utility workers and meets code requirements. We move essential circuits into a backup loads panel during installation. These circuits often include refrigeration, lighting, and internet. Most backup systems also support daily self-consumption. A backup reserve protects stored energy for outages. If you set a 70% reserve, the system cycles only 30% each day to save money and will always have 70% available for outages.
Meter Collars for Whole-Home Backup
New meter-collar products now support whole-home backup at a lower cost. They reduce extra equipment and installation labor. They also power more loads during outages. Some systems require more monitoring because more loads can run at once. Several manufacturers now offer smart controls. These controls automatically turn off large loads when the grid fails. This protects the battery and extends runtime during long outages.
Savings (Grid-Tied) Battery Design
A savings battery focuses on bill reduction instead of outage protection. It stores extra solar produced during the day and discharges during peak pricing. It also can run at night when solar is not available. Savings batteries do not require a transfer switch or a backup loads panel. Some systems, like Enphase, remove the transfer switch (system controller or meter collar) which reduces labor and material cost. Savings systems do not hold energy for outages. They often discharge down to 5% and use more capacity each day. This lets homeowners choose a smaller and more affordable battery.
by Mike Pane | Aug 30, 2023 | Battery Storage Systems, Uncategorized
Understanding kW and kWh in Battery Storage
Many people don’t understand the difference between kW and kWh, but the distinction matters. These two ratings appear on every battery system and help determine proper sizing. A useful analogy using a car compares kW to engine horsepower and kWh to a fuel tank size or EV driving range. “Kilo” means one thousand, so one kilowatt equals one thousand watts and one kilowatt-hour is 1,000 watts used over an hours time.
Whats a kW
A kW rating measures power, which shows how much electricity a device or battery can deliver at one time. A 1,000-watt microwave needs 1 kW to operate. A battery’s kW rating determines what you can run at the same time during an outage. Batteries also include a surge rating in kW, which handles short bursts of extra power. Surge ratings matter when starting pumps or motors that need higher startup loads.
Whats a kWh
A kWh measures energy used over time. A 100-watt bulb running for ten hours uses 1 kWh. A battery’s kWh rating shows how long it can supply power during an outage. This duration depends on which loads you use and how long they run. Your utility bills also track energy in kWh. Most home battery names use kWh as the main identifier. The Enphase 10C stores 10 kWh. Most systems allow stacking to increase total capacity as needed. Enphase 10C batteries can stack to 80 kWh. Some battery systems also increase power output (kW) as capacity (kWh) grows.
by Synergy Solar | Apr 28, 2021 | Battery Storage Systems, Solar Installation
Can I use my electric vehicle battery to power my home?
Often, I am asked “Why can’t I use my electric car to run my refrigerator or get hot water when the utility grid is down,” or “Why do I need an energy storage system (ESS) when I have a big battery in my electric car?” This is often called “Vehicle to Grid” or VTG. In this blog I will discuss the policies, practical applications, and costs of VTG as a replacement to a dedicated ESS and their possible roll in augmenting ESS. While these technologies are coming, I do not know of any jurisdictions in Sonoma County that are currently approving this technology.
To begin this discussion, it may be beneficial to first discuss how an ESS system works. When the utility grid is functioning
normally, my storage system charges from solar in the mornings when PG&E costs are low, and discharges in the early evening when PG&E rates are high. (We call this peak shaving.) This is one of the primary ways an ESS lowers home energy costs. An ESS can also provide homes with backup power when the utility goes down or is shut down for fire prevention. When my ESS senses no grid power, the automated transfer switch disconnects from PG&E and the ESS provides power to my home. When the utility power is restored, the transfer switch automatically reconnects to the grid and we return to normal operations. This ability to minimize the impact of the ever-increasing grid outages that we experience in northern California is the primary reason most of our customers add storage to their solar.
So now that we understand how a traditional ESS system works, let’s look at how it would differ with a VTG setup. The biggest problem is the battery’s dual use of both driving an EV (electric vehicle) and using it as the home battery back-up system. The battery cannot be in two places at the same time. Let’s look at a few examples:
- Recently during the Glass Fire, the residents of Oakmont were ordered to evacuate their homes. For the battery in their EV to operate as the ESS, these homeowners would need to leave their EV behind. This requires that they did not need this vehicle to evacuate and are willing to leave it in harm’s way so the vehicle’s battery could provide backup to the home.
- In the Kincade Fire, homeowners were not allowed back into the evacuation area for an extended period. If you were in your EV and not able to return to your home, there would be no back-up power to your home (leaving spoiled food in refrigerators and freezers).
- Let’s assume you drove your car to San Francisco and back, leaving just a minimum remaining charge in the vehicle. If the power goes out that evening, you will have very little battery for your home use, and then be stuck with a drained car battery.
So, one very big difference is reliability – with a VTG there is no guarantee the vehicle will be present, have available charge or be rechargeable from solar, all significant draw backs.
And the biggest benefit often brought up in VTG applications versus installing a separate backup battery is the cost savings – let’s take a look at that.
are several components of an ESS installation that would also be required in a VTG application. You would still need to install the following components which can make up well over half the ESS system cost:
- A transfer switch which disconnects the system from the utility in an outage and protects the grid, home electronics and utility lineman.
- An inverter to convert the DC power of the car to the AC power of the home.
- The electrical integration with either a connection to the entire home, or a protected load panel (PLP).
- Possible replacement of the existing car charger to a bi-direction charger since most chargers only allow power to flow one way – from the grid to the EV.
- The labor, permits, inspections and design costs.
- Online monitoring or automation of this system so it could work even if you were not at home, but the EV was.
Other considerations include the following:
- For a homeowner to receive the Residential Federal Solar Tax Credit on the VTG or ESS system, it must be charged from a solar system. Since most EVs are charge from the grid, they would not fall under the Residential Federal Solar Tax Credit.
- One of the benefits of ESS is the ability to charge from solar when utility rates are low and then to allow a homeowner to discharge from the ESS system when utility rates are high. VTG systems would not easily be able to do this since they would be driven during the day, and most likely charged from the grid at night.
- Would the EVs warranty be voided when it is used in a VTG application?
- Also, many jurisdictions have more stringent rules for home storage systems, and in some cases will not allow them to be installed in garages, which could preclude the use of VTG in these communities.
It is my belief that using VTG to replace a ESS system is not viable today, but as the technology changes, I do see a place for VTG integrating to ESS for residential use. The integration could provide multiple benefits.
- When the utility is down, the ESS system could control or limit charging to the EV so power from the ESS could first be used to run the home, and extra solar power (once battery are fully charged) could be used to charge the EV’s battery.
- Adding the EV battery to the ESS would allow for a greater resiliency (more KWH of battery available) for low light days from rain, fog or heavy smoke.
- Having portable energy storage – the ability to drive the car to another community, charge it and return home with more storage during long outages.
Summary:
some stand-alone VTG system do exist today which allow customers to plug in a refrigerator or charge a phone, they are very customized and include running extension cords to appliances. Most jurisdictions have not approved these applications which does raise safety concerns. While VTG is an emerging technology, currently it is years, maybe decades out before it is a viable alternative to or component of home ESS. It is my belief that VTG will have limited application but will become a critical add-on option to home energy storage systems.
by Synergy Solar | Sep 28, 2020 | Battery Storage Systems, Sonnen System Overviews
About Sonnen operating modes with Grid charging
Users have several different modes to choose from depending on their goals and usage. The sonnen battery system can charge from three primary sources; solar, the grid, or a generator (only in Back-Up mode). Which mode the sonnen is set to establishes the source of the energy in the battery. This blog will focus on modes of operation when the grid is up.
For purposes of this blog, I will be referencing sonnen’s Eco 10 or larger systems, and examples will be from my sonnen, an Eco 17.5 with a 9 kW solar system. My sonnen system feeds a protected load panel (PLP) which has the circuits I want backed up when the power is out.
There are three modes on a sonnen battery; Time of Use, Back Up, and Self-Consumption. Most of our users prefer the Time of Use (TOU) mode as it saves money daily, allows a buffer of stored energy for back-up power, and is arguably the most environmentally efficient. Back-Up mode is our second most popular option which maximizes back-up power stored for an outage and can also be used as a temporary option when outages are forecasted. Finally, Self-Consumption mode provides maximum autonomy from the grid, usually retains a smaller back-up buffer for outages, is considered environmentally efficient, and allows the maximum amount of power to be use/stored locally, minimizing importing or exporting to the grid.
Time of Use mode (TOU):
Let’s first look how the system works using the Time of Use mode. Sonnen is an AC coupled system, which means the solar first covers a home’s electrical loads before charging the batteries or exporting power to the grid. The order of using solar power is:
- Cover the household loads
- Charge the battery system
- Export excess power to the grid
For example, it is currently August and my solar system usually turns on around 7am. On sunny days, by 8am my solar power is producing more then my home needs and so my battery begins charging. My sonnen system can charge at up to 7 KW (kilo watt), which means my 17.5 KWH sonnen can be fully charged from solar on a sunny day in just over two hours and my system is usually fully charged by about 10:30am. From 10:30am until about 6:30pm I export power to the grid, receiving credits based on my PG&E rate schedule (I am on EV2).
At 6:30pm, rather than buying expensive power from Sonoma Clean Power/PG&E, I “peak shave” and use my battery power charged by solar, instead of the utility. At midnight my sonnen system gets to rest, and power for the home is imported from the grid (while it is least expensive) until my solar wakes up and begins a new day. I can also set a back-up buffer. (On my system, due to the current fires in the area I have mine set to 75%.)
Back-up buffer sets a State of Charge (SOC) floor and it will not discharge past that floor allowing me a comfortable safety net in case the power goes out. Another option available is to enable grid charging, which will allow you to charge at 250 watts per hour from the grid, per battery module during low tariff /cost windows. In most of our systems, this feature is turned off, meaning we are charging the battery from solar only.
Self-Consumption mode:
Self-consumption mode operates almost exactly as Time of Use mode, except it is not based on time (Time of Use mode is often called partial self-consumption.) In Self-Consumption mode, as long as solar power exceeds usage, the system uses solar to power the home. When consumption exceeds solar production, it will first discharge from the battery system down to your reserve buffer setting, regardless of the time of day (and PG&E rates) before drawing from the grid. So using my house as an example, if I were in Self-consumption mode, at midnight rather than my battery turning off in the example above, it would continue to discharge the battery until the solar system produces more power than my house uses or until my SOC reaches my reserve buffer. Self-Consumption does allow maximum autonomy from the utility, however this mode is the least popular option of our users as it is not as efficient or financial advantageous as TOU and leaves a smaller buffer reserve then backup mode.
Back-Up mode:
The sonnen system can also be set into Back-Up mode, saving 100% of the battery for power outages. Some of our customers have their system always in this mode, while others put it into this mode when PG&E announces a Public Safety Power Shut-off (PSPS), when rolling black outs are announce, or when other disasters occur. In Back-Up mode, the system will charge the battery from the moment it is activated, regardless of time, and will use the grid and/or solar. The charge rate in Back-Up mode is 250 watts per battery module (an Eco 10, Generation 3.1 system has 4, 2.5 KWH battery modules) and can take between 8-10 hours to fully charge batteries without solar. In this mode it will keep the batteries charged at 100% until it senses the grid is down when it will power your PLP circuits and recharge from your solar.
Modified Time of Use mode:
Another option that is very similar and more cost effective, is to stay in TOU mode and move the reserve buffer to 100%. This still keeps your battery at a 100% charge, but will only charge from the grid during low cost tariffs. In TOU mode you can also either disable grid charging so it is only charges from solar or enable grid charging which will charge at 250 watts per module, with or without the solar.
One final tip I like to recommend is to remember the primary purpose for buying your storage system. If the primary purpose was to save money, you should be in a TOU mode with a low buffer. If your primary goal is to have power when the grid is down, you should be in TOU mode with a high buffer, or you should be in Back-Up mode. Personally, I prefer to run my system in TOU mode. My battery and solar usually cover all of my PLP usage during high tariff windows (3 pm to midnight). This not only saves money, but it also minimizes the need for natural gas driven peaker plants, reduces the demand on utility infrastructure and still provides me a good buffer for power outages.
